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1

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

Microsoft Academic Search

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

B. Delbreil; M. Jullien

1994-01-01

2

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

3

Induced expression of AtLEC1 and AtLEC2 differentially promotes somatic embryogenesis in transgenic tobacco plants.  

PubMed

Arabidopsis LEAFY COTYLEDON (LEC) genes, AtLEC1 and AtLEC2, are important embryonic regulators that play key roles in morphogenesis and maturation phases during embryo development. Ectopic expression of AtLEC1 and AtLEC2 in tobacco caused abnormality in transgenic seedling. When transgenic seeds germinated on medium containing 30 µM DEX, LEC1 transgenic seedlings were ivory and fleshy, with unexpanded cotyledons, stubby hypocotyls, short roots and no obvious callus formation at the shoot meristem position. While LEC2 transgenic seedlings formed embryonic callus on the shoot apical meristem and somatic embryo-like structures emerged from the surface of the callus. When callus were transferred to hormone free MS0 medium more shoots were regenerated from each callus. However, shoot formation was not observed in LEC1 overexpressors. To investigate the mechanisms of LEC2 in somatic embryogenesis, we studied global gene expression by digital gene expression profiling analysis. The results indicated that ectopic expression of LEC2 genes induced accumulation of embryo-specific proteins such as seed storage proteins, late embryogenesis abundant (LEA) proteins, fatty acid biosynthetic enzymes, products of steroid biosynthesis related genes and key regulatory genes of the embryo development. Genes of plant-specific transcription factors such as NAC domain protein, AP2 and GRAS family, resistance-related as well as salicylic acid signaling related genes were up-regulated in LEC2 transgenic seedlings. Ectopi c expression of LEC2 induced large number of somatic embryo formation and shoot regeneration but 20 d DEX induction of LEC1 is not sufficient to induce somatic embryogenesis and shoot formation. Our data provide new information to understand the mechanisms on LEC2 gene's induction of somatic embryogenesis. PMID:23951228

Guo, Fengdan; Liu, Chuanliang; Xia, Han; Bi, Yuping; Zhao, Chuanzhi; Zhao, Shuzhen; Hou, Lei; Li, Fuguang; Wang, Xingjun

2013-01-01

4

Induced Expression of AtLEC1 and AtLEC2 Differentially Promotes Somatic Embryogenesis in Transgenic Tobacco Plants  

PubMed Central

Arabidopsis LEAFY COTYLEDON (LEC) genes, AtLEC1 and AtLEC2, are important embryonic regulators that play key roles in morphogenesis and maturation phases during embryo development. Ectopic expression of AtLEC1 and AtLEC2 in tobacco caused abnormality in transgenic seedling. When transgenic seeds germinated on medium containing 30 µM DEX, LEC1 transgenic seedlings were ivory and fleshy, with unexpanded cotyledons, stubby hypocotyls, short roots and no obvious callus formation at the shoot meristem position. While LEC2 transgenic seedlings formed embryonic callus on the shoot apical meristem and somatic embryo-like structures emerged from the surface of the callus. When callus were transferred to hormone free MS0 medium more shoots were regenerated from each callus. However, shoot formation was not observed in LEC1 overexpressors. To investigate the mechanisms of LEC2 in somatic embryogenesis, we studied global gene expression by digital gene expression profiling analysis. The results indicated that ectopic expression of LEC2 genes induced accumulation of embryo-specific proteins such as seed storage proteins, late embryogenesis abundant (LEA) proteins, fatty acid biosynthetic enzymes, products of steroid biosynthesis related genes and key regulatory genes of the embryo development. Genes of plant-specific transcription factors such as NAC domain protein, AP2 and GRAS family, resistance-related as well as salicylic acid signaling related genes were up-regulated in LEC2 transgenic seedlings. Ectopi c expression of LEC2 induced large number of somatic embryo formation and shoot regeneration but 20 d DEX induction of LEC1 is not sufficient to induce somatic embryogenesis and shoot formation. Our data provide new information to understand the mechanisms on LEC2 gene’s induction of somatic embryogenesis. PMID:23951228

Xia, Han; Bi, Yuping; Zhao, Chuanzhi; Zhao, Shuzhen; Hou, Lei; Li, Fuguang; Wang, Xingjun

2013-01-01

5

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

6

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

7

Thidiazuron induces shoot organogenesis at low concentrations and somatic embryogenesis at high concentrations on leaf and petiole explants of African violet (Saintpaulia ionantha Wendl).  

PubMed

Regeneration via shoot organogenesis and somatic embryogenesis was observed from thidiazuron (TDZ)-treated leaf and petiole explants of greenhouse- and in vitro-grown African violet plants. The response of cultures to other growth regulators over a range of 0.5 microM to 10 microM was 50% less than that observed with TDZ. A comparative study among several cultivars of African violet indicated that "Benjamin" and "William" had the highest regeneration potential. In "Benjamin", higher frequencies of shoot organogenesis (twofold) and somatic embryogenesis (a 50% increase) were observed from in vitro- and greenhouse-grown plants, respectively. At concentrations lower than 2.5 microM, TDZ induced shoot organogenesis, whereas at higher doses (5-10 microM) somatic embryos were formed. These findings provide the first report of simultaneous shoot organogenesis and somatic embryogenesis of African violet explants in response to TDZ. PMID:12789442

Mithila, J; Hall, J C; Victor, J M R; Saxena, P K

2003-01-01

8

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

9

Repetitive somatic embryogenesis from peanut cultures in liquid medium  

Microsoft Academic Search

Summary  A regeneration system based on repetitive somatic embryogenesis was developed for peanut (Arachis hypogaea L.). Embryogenic suspension cultures were initiated using individual somatic embryos induced from immature cotyledons cultured on a modified Murashige and Skoog medium containing 40 mg\\/l 2,4-D for 30 days. After transfer to a modified MS liquid medium, the somatic embryos produced masses of secondary and tertiary

Richard E. Durham; Wayne A. Parrott

1992-01-01

10

Secondary somatic embryogenesis and plant regeneration in cassava  

Microsoft Academic Search

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

James A. Stamp; Graham G. Henshaw

1987-01-01

11

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

12

Somatic Embryogenesis in Genera Medicago : an Overview  

Microsoft Academic Search

This chapter outlines the details of somatic embryogenesis in genera Medicago.\\u000a Various factors that influence the process of somatic embryo induction, development, maturation and\\u000a conversion are discussed. The role of genotype, explant choice and preparation hormonal compositions\\u000a and the origin of somatic embryos are also reviewed. Brief attention is paid to the regenerant's\\u000a phenotype and fertility.

A. Iantcheva; M. Vlahova; A. Atanassov

13

Somatic Embryogenesis in Four Tree Legumes  

PubMed Central

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

Das, Premananda

2011-01-01

14

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

15

Somatic embryogenesis from peach palm zygotic embryos  

Microsoft Academic Search

The factors affecting the induction and development of somatic embryos and plantlet acclimatization of peach palm (Bactris gasipaes Kunth) were evaluated to establish an efficient regenerative protocol based on somatic embryogenesis. Mature zygotic embryos\\u000a were cultured in Murashige and Skoog (MS) medium supplemented with 0–40 ?M of picloram (4-amino-3,5,6-trichloropicolinic acid)\\u000a and 0 or 5 ?M of 2-isopentyladenine (6-dimethylaminopurine) (2-iP). After 5 mo. in

D. A. Steinmacher; G. C. Cangahuala-Inocente; C. R. Clement; M. P. Guerra

2007-01-01

16

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

17

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

18

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

19

Somatic embryogenesis from integument (perisperm) cultures of coffee  

Microsoft Academic Search

Somatic embryogenesis was induced in integument (perisperm) cultures of C x R hybrid cultivar of coffee, after a culture period of 15 months, using a sequence of 3 modifications of MS medium. Vigorously growing soft, white, watery crystalline calli were obtained on MS + TIBA (1 mg\\/l) + L-cysteine HCl (50 mg\\/l) + PVP (100 mg\\/l). After 45 d, the

H. L. Sreenath; H. M. Shanta; K. Harinath Babu; M. M. Naidu

1995-01-01

20

Genetic variation in somatic embryogenesis of Rosa Hybrida L.  

E-print Network

' and 'Baby Love' were cultured on somatic embryogenesis induction media and evaluated for the ability to produce embryogenic callus. Cultures of 'Tournament of Roses' produced somatic embryos at a much higher frequency versus 'Baby Love' that produced...

Burrell, Anna Mildred

2004-09-30

21

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

22

Somatic Embryogenesis in Some Cactus and Agave Species  

Microsoft Academic Search

Somatic embryogenesis is an asexual form of plant propagation in nature that mimics many of the events of sexual reproduction. Also, this process may be reproduced artificially by the manipulation of tissues and cells in vitro. Some of the most important factors for a successful plant regeneration are the culture medium and environmental incubation conditions. In vitro somatic embryogenesis is

Fernando Santacruz-Ruvalcaba; Antonia Gutiérrez-Mora; Benjamín Rodríguez-Gara

23

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

24

Somatic embryogenesis of Agave victoria-reginae Moore  

Microsoft Academic Search

Plant regeneration through direct somatic embryogenesis of leaf blade explants from in vitro propagated plants of Agave victoria-reginae Moore, is described. Somatic embryogenesis was evident in a 6-week period on agarsolidified MS medium supplemented with L2 vitamins and 2,4-dichlorophenoxyacetic acid (1,4 µM), and germination of somatic embryos was achieved after 8 weeks on half-strength MS medium and 4 weeks on

Benjamin Rodríguez-Garay; Antonia Gutiérrez-Mora; Beatríz Acosta-Duefias

1996-01-01

25

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

26

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

27

Plant regeneration through direct somatic embryogenesis from leaf explants of Dendrobium  

Microsoft Academic Search

A protocol for induction of direct somatic embryogenesis, secondary embryogenesis and plant regeneration of Dendrobium cv. Chiengmai Pink was developed. Thidiazuron (TDZ) at 0.3, 1 and 3 mg dm?3 induced 5–25 % of leaf tip segments of in vitro grown plants to directly form embryos after 60 d of culture, and 1 mg dm?3 TDZ was the best treatment. Somatic

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

2007-01-01

28

Somatic embryogenesis and plant regeneration in Opuntia ficus-indica (L.) Mill. (Cactaceae)  

Microsoft Academic Search

We present here a method for the regeneration of the prickly-pear (Opuntia ficus-indica (L.) Mill.) through somatic embryogenesis (SE). Direct SE was induced by cultivating shoot apices devoid of leaf primordia on semisolid Murashige and Skoog (MS) basal medium supplemented with 4-amino 3,5,6-trichloropicolinic acid (picloram) at 4mgl?1. Somatic embryogenesis was influenced by the type, age, physiological and developmental stage of

Francisco Linhares Arruda Ferreira Gomes; Fabíola Fernandes Heredia; Priscilla Barbeta e Silva; Olivardo Facó; Francisco de Assis de Paiva Campos

2006-01-01

29

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

30

Localization of calcium during somatic embryogenesis of carrot ( Daucus carota L.)  

Microsoft Academic Search

Summary The distribution of free cytosolic Ca2+ was studied during somatic embryogenesis of carrot using confocal scanning laser microscopy with fluo-3 as a fluorescent Ca2+ indicator. Chlorotetracycline fluorescence, antimonate precipitation and proton induced X-ray emission analysis were used as additional methods to confirm the results obtained with fluo-3. The process of embryogenesis was found to coincide with a rise in

A. C. J. Timmers; H.-D. Reiss; J. Bohsung; K. Traxel; J. H. N. Schel

1996-01-01

31

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

PubMed

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. PMID:24494238

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

2013-10-01

32

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. PMID:24169428

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

2013-01-01

33

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

E-print Network

ENHANCING THE FREQUENCY OF SOMATIC EMBRYOGENESIS FOLLOWING AGROBACTERIUM-MEDIATED TRANSFORMATION embryogenic explants along with the location of embryogenesis- and transformation-competent cells embryogenesis on immature cotyledons following Agrobacterium tumefaciens-mediated transformation and selection

Korban, Schuyler S.

34

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

PubMed Central

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

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

2011-01-01

35

Somatic embryogenesis and plant regeneration from stem explants of Moricandia arvensis  

Microsoft Academic Search

Efficient and reproducible plant regeneration has been established from stem internode explants of Moricandia arvensis, a crucifer of special interest due to its C3-C4 intermediate photosynthetic activity. Somatic embryogenesis was induced in one-third of explants cultured on Murashige and\\u000a Skoog based medium containing 9 mm 2,4-dichlorophenoxyacetic acid. High frequencies of plant regeneration (>90%) resulted when somatic embryos were germinated\\u000a on

W. Craig; A. Wiegand; C. M. O'Neill; R. J. Mathias; J. B. Power; M. R. Davey

1997-01-01

36

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

37

Clonal propagation of Cyclamen persicum via somatic embryogenesis.  

PubMed

Cyclamen (Cyclamen persicum) is an economically important ornamental pot plant with local use as cut flower as well. Traditionally, it is propagated via seeds, but interest is given in vegetative propagation of parental lines as well as superior single plants. Somatic embryogenesis is an efficient in vitro propagation method for many cyclamen cultivars. Starting from ovules of unpollinated flowers, callus is induced and propagated in a medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-(gamma,gamma-dimethylallylamino)purine (2iP). Transfer to hormone-free medium results in the differentiation of somatic embryos, which afterwards germinate on the same medium. These first culture stages take about 6-7 months and are carried out in complete darkness. Two to four months after the transfer to light, plantlets develop which can be acclimatized in the greenhouse. The regenerated plants are characterized by low percentages of somaclonal variation. This protocol has proven useful not only for clonal propagation, but also for artificial seed preparation, cryopreservation, genetic transformation and protoplast regeneration. PMID:20099110

Winkelmann, Traud

2010-01-01

38

Molecular characterization of a Cyrtochilum loxense Somatic Embryogenesis Receptor-like Kinase (SERK) gene expressed during somatic embryogenesis.  

PubMed

Somatic embryogenesis is crucial for the propagation of endangered Ecuadorian orchid species, among them Cyrtochilum loxense, in view of the fact that their number in nature or in collections is quite reduced. One of the genes expressed during somatic and zygotic embryogenesis is Somatic Embryogenesis Receptor-like Kinase (SERK). Despite the development of somatic embryogenesis protocols for orchids, no SERK genes have been isolated from this family. This is the first report on the isolation of a full-length orchid SERK sequence, namely that of Cyrtochilum loxense (ClSERK). The identity of ClSERK was inferred by the presence of all domains typical of SERK proteins: a signal peptide, a leucine zipper domain, five LRRs, a serine proline-rich domain, a transmembrane domain, a kinase domain, and the C-terminal region. We have observed that the ClSERK gene is highly expressed in embryogenic calluses generated from protocorms at the time of appearance of embryonic morphological features. At later stages when embryos become well visible on calluses, ClSERK gene expression decreases. Compared to early stages of embryo formation on calluses, the expression detected in leaf tissue is far lower, thus suggesting a role of this gene during development. PMID:22350407

Cueva, Augusta; Concia, Lorenzo; Cella, Rino

2012-06-01

39

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

PubMed

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

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

2010-07-01

40

An efficient regeneration system via somatic embryogenesis in olive  

Microsoft Academic Search

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

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

2011-01-01

41

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

42

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

43

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

Microsoft Academic Search

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 a-naphthaleneacetic acid plus KN or 1–1.5 mg l -1benzylaminopurine (BAP) or 0.25–0.5 mg l -12,4-dichlorophenoxyacetic acid

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

2003-01-01

44

In vitro regeneration of Irvingia gabonensis by somatic embryogenesis.  

PubMed

A productive genotype of Irvingia gabonensis were cultured in vitro for induction embryogenic calli, somatic embryogenesis and regeneration of plantlets. Fragments of young leaves were used as primary explants. Callogenesis was initiated by culture of explants during 30 days on Murashige and Skoog medium half strength (MS/2) supplemented with 1-6 mg L(-1) of 2,4-dichlorophenoxyacetic acid (2,4-D). The highest percentage of explants forming calli is 85.1% at 3 mg L(-1) of 2,4-D. Somatic embryos were obtained after a subculture of embryogenic calli during 60 days on MS/2 supplemented with 1-3 mg L(-1) of BAP. The highest percentage of embryogenic calli which differentiates somatic embryos is 63.8 +/- 2.3% at 1 mg L(-1) of 6-benzylaminopurine (BAP). The highest number of somatic embryos per callus which is 43.6 is obtained with 2 mg L(-1) of this phytohormone. When isolated from calli and sub-cultured during 30 days on MS/2 supplemented with 2 mg L(-1) of BAP, somatic embryos germinate with a highest percentage of 83%. The subculture of germinated somatic embryos on the same Basal Medium (BM) supplemented with 4 mg L(-1) of BAP and 2 mg L(-1) of Naphthalene Acetic Acid (NAA) during 80 days gives rise to the plantlets with 82.7 +/- 4.8% of success. With this combination, each plantlet has average length of 5.6 cm, bears 3.3 leaves and 7.2 roots with 1 or 2 pivoting roots. Plantlets acclimatized on a mixture sterilized soil/vermiculite at equal volume survive at 93%. Results of this study constitute a new way for a production of Irvingia gabonensis seedlings with pivoting root and they permit to arrest the difficulties of natural and horticultural reproduction. PMID:18819568

Fotso; Oumar; Nicolas, Niemenak; Néhémie, Donfagsiteli Tchinda; Denis, Omokolo Ndoumou

2008-03-01

45

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

46

LEAFY COTYLEDON1 , FUSCA3 expression and auxin treatment in relation to somatic embryogenesis induction in Arabidopsis  

Microsoft Academic Search

The expression pattern of the LEC1 and FUS3 genes during somatic embryogenesis in Arabidopsis explants (immature zygotic embryos) induced in vitro was analysed, using\\u000a Real-time quantitative PCR (qRT-PCR). The analysis revealed differential expression of LEC1 but not FUS3 within a 30 day time course of somatic embryo development, and a significant auxin-dependent upregulation of LEC1 was found over the time course.

Agnieszka Ledwo?; Malgorzata D. Gaj

47

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

Microsoft Academic Search

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

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

2006-01-01

48

DNA methylation during sexual embryogenesis and implications on the induction of somatic embryogenesis in Castanea sativa Miller.  

PubMed

From anthesis to mature seed formation, burrs from cross-pollinated adult Castanea sativa Miller trees were characterized and seven developmental stages defined based on macro and micromorphological traits. In order to get an insight into the involvement of epigenetic mechanisms in sexual embryogenesis and to define somatic embryogenesis induction capability, global DNA methylation and the somatic embryogenic competence were quantified. On cross-pollinated trees once fertilization takes place, at least one ovule per ovary becomes dominant, and transient DNA demethylation occurs coinciding with the start of the sexual embryogenic programme. Unfertilized ovules from the same cluster, which maintain their prior size, increase their methylation level and undergo degeneration. These results were validated using non-cross-pollinated trees and the asynchrony of flower receptivity. When testing in vitro somatic embryogenesis response of isolated dominant ovules and axes from zygotic embryos under cross-pollinated conditions, the highest competence was found for reaching seed maturity. Thus, a "developmental window" of somatic embryogenesis in chestnut has been characterized. It includes from fertilization to embryo maturity, and a transient decrease in methylation is necessary after fertilization for the development of the somatic embryogenesis response. PMID:20552230

Viejo, M; Rodríguez, R; Valledor, L; Pérez, M; Cañal, M J; Hasbún, R

2010-12-01

49

Somatic embryogenesis and plant regeneration in the culture of Arabidopsis thaliana (L.) Heynh. immature zygotic embryos.  

PubMed

Immature zygotic embryos (IZEs) of Arabidopsis thaliana (L.) Heynh., a model species for plant -genomics, provide efficient explants for a simple, rapid, and effective system for inducing somatic embryogenesis (SE) under in vitro culture. The process of SE can be induced directly from explant tissue, or indirectly through a callus stage, and the mode of morphogenesis depends on the developmental stage of the IZEs that are used. Auxin treatment, preferably with 2,4-D, results in the formation of embryogenic callus tissue in cultures derived from IZEs less advanced in development, i.e., at globular and torpedo stages, while IZE at the late cotyledonary stage rapidly produces somatic embryos, mostly via a direct pathway. In the best SE-responsive genotypes, including the commonly used Col-0 ecotype, up to 90% of the late cotyledonary-stage zygotic embryos undergo rapid and efficient SE. The subculture of somatic embryos onto auxin-free medium results in their conversion into plantlets with an average frequency of 80%. Such a high frequency of somatic embryos developing rapidly from explant tissue, followed by efficient regeneration of fertile plants with a low level of somaclonal variation, is the recommended system for wide application in studies on mechanisms governing plant totipotency; and especially for identifying genetic factors controlling embryogenic transition of somatic plant cells. In this chapter, the induction, development, and maturation of somatic embryos leading to subsequent regeneration of Arabidopsis plantlets in culture of IZEs are presented. PMID:21207274

Gaj, Malgorzata D

2011-01-01

50

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

51

Tobacco Arabinogalactan Protein NtEPc Can Promote Banana (Musa AAA) Somatic Embryogenesis.  

PubMed

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

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

2014-12-01

52

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

53

Expression and Function of Cell Wall-Bound Cationic Peroxidase in Asparagus Somatic Embryogenesis  

PubMed Central

Cultured asparagus (Asparagus officinalis L. cv Y6) cells induced to regenerate into whole plants through somatic embryogenesis secreted a 38-kD protein into cell walls. The full-length cDNA sequence of this protein (Asparagus officinalis peroxidase 1 [AoPOX1]) determined by reverse transcriptase-polymerase chain reaction showed similarity with plant peroxidases. AoPOX1 transcripts were particularly abundant during early somatic embryogenesis. To evaluate the in vivo function of AoPOX1 protein, purified recombinant AoPOX1 protein was reacted with a series of phenolic substrates. The AoPOX1 protein was effective in the metabolism of feruloyl (o-methoxyphenol)-substituted substrates, including coniferyl alcohol. The reaction product of coniferyl alcohol was fractionated and subjected to gas chromatography-mass spectrometry analysis and 1H-nuclear magnetic resonance analysis, indicating that the oxidation product of coniferyl alcohol in the presence of AoPOX1 was dehydrodiconiferyl alcohol. The concentration of dehydrodiconiferyl alcohol in the cultured medium of the somatic embryos was in the range of 10?8 m. Functions of the AoPOX1 protein in the cell differentiation are discussed. PMID:12692335

Takeda, Hiroyuki; Kotake, Toshihisa; Nakagawa, Naoki; Sakurai, Naoki; Nevins, Donald J.

2003-01-01

54

Expression and function of cell wall-bound cationic peroxidase in asparagus somatic embryogenesis.  

PubMed

Cultured asparagus (Asparagus officinalis L. cv Y6) cells induced to regenerate into whole plants through somatic embryogenesis secreted a 38-kD protein into cell walls. The full-length cDNA sequence of this protein (Asparagus officinalis peroxidase 1 [AoPOX1]) determined by reverse transcriptase-polymerase chain reaction showed similarity with plant peroxidases. AoPOX1 transcripts were particularly abundant during early somatic embryogenesis. To evaluate the in vivo function of AoPOX1 protein, purified recombinant AoPOX1 protein was reacted with a series of phenolic substrates. The AoPOX1 protein was effective in the metabolism of feruloyl (o-methoxyphenol)-substituted substrates, including coniferyl alcohol. The reaction product of coniferyl alcohol was fractionated and subjected to gas chromatography-mass spectrometry analysis and (1)H-nuclear magnetic resonance analysis, indicating that the oxidation product of coniferyl alcohol in the presence of AoPOX1 was dehydrodiconiferyl alcohol. The concentration of dehydrodiconiferyl alcohol in the cultured medium of the somatic embryos was in the range of 10(-8) M. Functions of the AoPOX1 protein in the cell differentiation are discussed. PMID:12692335

Takeda, Hiroyuki; Kotake, Toshihisa; Nakagawa, Naoki; Sakurai, Naoki; Nevins, Donald J

2003-04-01

55

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

56

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

PubMed

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

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

2013-01-01

57

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

Microsoft Academic Search

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

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

2007-01-01

58

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

59

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

PubMed

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 from the root pole of newly formed embryos resulting in clumps of somatic embryos. Strength of the medium and sucrose concentration influenced the process of secondary embryogenesis and fresh weight of somatic embryo clumps. Full-strength SH medium supplemented with 1.5% sucrose produced significantly higher fresh weight and numbers of secondary somatic embryos while 3.0 and 4.5% sucrose in the medium favored further development of proliferated embryos into plantlets. Ontogeny of secondary embryos was established by histological analysis. Secondary embryogenic potential was influenced by the developmental stage of the explanted somatic embryo and stages up to "torpedo" were more suitable. A single-flask system was standardized for proliferation, maturation, germination and conversion of secondary somatic embryos in suspension cultures. The system of cyclic secondary somatic embryogenesis in black pepper described here represents a permanent source of embryogenic material that can be used for genetic manipulations of this crop species. PMID:16249871

Nair, R Ramakrishnan; Dutta Gupta, S

2006-01-01

60

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

61

Somatic embryogenesis and plant regeneration in Cyphomandra betacea (Cav.) Sendt  

Microsoft Academic Search

Callus cultures with globular proembryogenic structures were induced from zygotic embryos and hypocotyl segments of Cyphomandra betacea on MS medium supplemented with 2,4-D. Proembryogenic structures produced somatic embryos and plantlets on regulator-free basal medium. Pieces of embryogenic callus subcultured on medium with the same original composition gave rise to new globular structures and the potential for plantlet regeneration has been

Maria Ludovina S. Guimarães; Gil S. Cruz; João M. Montezuma-De-Carvalho

1988-01-01

62

Somatic embryogenesis and plant regeneration in Catharanthus roseus  

Microsoft Academic Search

Embryogenic callus in Catharanthus roseus was initiated from hypocotyl on Murashige and Skoog’s (MS) medium supplemented with 1.0–2.0 mg dm?3 of 2,4-dichlorophenoxyacetic acid (2,4-D) or chlorophenoxyacetic acid (CPA). Calli from other sources were non-embryogenic.\\u000a Numerous somatic embryos were induced from primary callus on MS medium suplemented with naphthalene acetic acid (NAA) within\\u000a two weeks of culture. Embryo proliferation was much

A. Junaid; A. Mujib; M. A. Bhat; M. P. Sharma; J. Šamaj

2007-01-01

63

Somatic embryogenesis and plant regeneration from different wild diploid cotton (Gossypium) species.  

PubMed

Calli were successfully induced from hypocotyls of eight wild diploid cotton species (Gossypium) on MSB (MS salts and B(5) vitamins) medium supplemented with 0.09 microM 2,4-D (2,4-dichlorophenoxyacetic acid) and 2.32 microM KT (kinetin). Plant growth regulator (PGR) combinations, adding GA(3) (Gibberellic acid), high inorganic salt stress, and PGR-free media were used to induce embryogenic calli from nonembryogenic calli. Embryogenic cultures were induced from G. aridum S. (D(4) genome), G. davidsonii K. (D(3)-d genome), G. klotzschianum A. (D(3)-k genome), G. raimondii U. (D(5) genome), and G. stocksii M. (E(1) genome). We then observed somatic embryogenesis in the five species while calli of G. africanum V. (A(1)-2 genome), G. anomalum W. (B(1) genome), and G. bickii P. (G genome) remained nonembryogenic. Somatic embryogenesis was adjusted by changing sugar sources, regulating combinations of PGRs, and using cell suspension culture. Embryos at various developmental stages produced mature and germinating embryos when cultured on filter paper placed on the media containing different sugar sources. The utility of different sugar sources promoted globular embryos developing into cotyledonary stage and increased the frequency of cotyledonary embryos developing into normal plants. Normal plantlets were regenerated from G. davidsonii, G. klotzschianum, G. raimondii, and G. stocksii. Only abnormal plantlets were obtained in G. aridum. This work will contribute to broadening the number of regenerable cotton species and provide foundations for somatic hybridization in cotton to create new germplasm. PMID:16315034

Sun, Yuqiang; Zhang, Xianlong; Huang, Chao; Guo, Xiaoping; Nie, Yichun

2006-04-01

64

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

Microsoft Academic Search

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

Jean-Vincent Escalant; Claude Teisson; François Cote

1994-01-01

65

N-Acetylglucosamine and Glucosamine-Containing Arabinogalactan Proteins Control Somatic Embryogenesis1  

PubMed Central

In plants, complete embryos can develop not only from the zygote, but also from somatic cells in tissue culture. How somatic cells undergo the change in fate to become embryogenic is largely unknown. Proteins, secreted into the culture medium such as endochitinases and arabinogalactan proteins (AGPs) are required for somatic embryogenesis. Here we show that carrot (Daucus carota) AGPs can contain glucosamine and N-acetyl-d-glucosaminyl and are sensitive to endochitinase cleavage. To determine the relevance of this observation for embryogenesis, an assay was developed based on the enzymatic removal of the cell wall from cultured cells. The resulting protoplasts had a reduced capacity for somatic embryogenesis, which could be partially restored by adding endochitinases to the protoplasts. AGPs from culture medium or from immature seeds could fully restore or even increase embryogenesis. AGPs pretreated with chitinases were more active than untreated molecules and required an intact carbohydrate constituent for activity. AGPs were only capable of promoting embryogenesis from protoplasts in a short period preceding cell wall reformation. Apart from the increase in embryogenesis, AGPs can reinitiate cell division in a subpopulation of otherwise non-dividing protoplasts. These results show that chitinase-modified AGPs are extracellular matrix molecules able to control or maintain plant cell fate. PMID:11299367

van Hengel, Arjon J.; Tadesse, Zewdie; Immerzeel, Peter; Schols, Henk; van Kammen, Ab; de Vries, Sacco C.

2001-01-01

66

Somatic embryogenesis and regeneration of plantlets in protoplast cultures from somatic embryos of coffee (Coffea canephora P. ex Fr.)  

Microsoft Academic Search

Somatic embryogenesis was achieved in protoplast cultures of coffee. Protoplasts were isolated from cell suspension-derived somatic embryos of Coffea canephora. After repeated subculture in a medium supplemented with 0.5 mg\\/l of each of kinetin, 2,4-dichlorophenoxyacetic acid (2,4-D), and naphthaleneacetic acid (NAA), microcalli developed. Transfer of these microcalli to a medium lacking growth regulators resulted in the formation of globular embryos.

Christian Schöpke; Ludwig E. Müller; Hans-Willy Kohlenbach

1987-01-01

67

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

68

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

PubMed Central

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

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

2014-01-01

69

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

PubMed

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

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

2014-01-01

70

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

Microsoft Academic Search

The effect of different carbohydrates was tested on early somatic embryogenesis of Hevea brasiliensis. Sucrose was replaced with maltose, fructose or glucose. Somatic embryo production was significantly higher with maltose.\\u000a With maltose, the initial yellow colour of the calli turned orange, and dry matter production after 28 days' culture was half\\u000a that obtained with sucrose. Maltose also reduced the soluble

G. Blanc; N. Michaux-Ferrière; C. Teisson; L. Lardet; M. P. Carron

1999-01-01

71

Regeneration of diploid annual medics via direct somatic embryogenesis promoted by thidiazuron and benzylaminopurine  

Microsoft Academic Search

The development of a simple and rapid procedure for direct somatic embryogenesis from wild Medicago spp. (M. truncatula, M. littoralis, M. murex, M. polymorpha) has exploited various explants including meristematic zones. Phytogel-solidified medium supplemented with thidiazuron or\\u000a 6-benzylaminopurine at different concentrations effectively promoted this process. The first somatic structures emerged within\\u000a 20 days of culture initiation. Histological analyses confirmed the

A. Iantcheva; M. Vlahova; E. Bakalova; E. Kondorosi; M. C. Elliott; A. Atanassov

1999-01-01

72

Regeneration of coconut (Cocos nucifera L.) from plumule explants through somatic embryogenesis  

Microsoft Academic Search

A protocol was developed for coconut regeneration using plumules from mature zygotic embryos as explants, and media with\\u000a the synthetic growth regulators 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine. Evidence for the regeneration process\\u000a from these tissues occurring through somatic embryogenesis is presented. The somatic embryos were capable of germination,\\u000a subsequent development into plantlets and successful transfer to the nursery. The yields were

J. L. Chan; L. Saénz; C. Talavera; R. Hornung; M. Robert; C. Oropeza

1998-01-01

73

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

PubMed

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

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

2012-10-01

74

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

Microsoft Academic Search

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

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

2011-01-01

75

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

Microsoft Academic Search

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

Clément Thomas; Víctor Jiménez

76

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

77

Asexual reproduction, regeneration, and somatic embryogenesis in the planarian Dugesia tigrina (Turbellaria)  

Microsoft Academic Search

In reviewing recent research published in Russian on regeneration and asexual reproduction, the following morphogenetic processes in the planarian Dugesia tigrina are considered: 1) regeneration of lost parts of the body; 2) regeneration of the whole worm from fragments of the body, either by normal regeneration when the inital polarity of the fragment is retained or by somatic embryogenesis when

Elena B. Krichinskaya

1986-01-01

78

Research note Putrescine enhances somatic embryogenesis and plant regeneration in upland  

E-print Network

with culture media containing various Putrescine concentrations. The best results were obtained with the a significantly lower for these lines as compared to the standard cultivar for cotton transformation, `Coker 312/maturation media on somatic embryogenesis and regeneration potential in cot- ton. The plant materials consisted

Chee, Peng W.

79

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

PubMed Central

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

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

2003-01-01

80

[Changes in polyamine levels in Citrus sinensis Osb. cv. Valencia callus during somatic embryogenesis].  

PubMed

Somatic embryogenetic capability and changes in polyamine level and their relationship were analyzed using the long-term (8 years) subcultured calli of Citrus sinensis Osb. cv. Valencia as materials. The results showed that endogenous polyamine contents in embryogenic calli were higher than those in non-embryogenic calli, and the embryogenetic capability was positively correlated to the levels of endogenous polyamines. When the calli were transferred to a differentiation medium, the putrescine content rapidly increased and reached a peak, then fell gradually. Applying exogenous putrescine raised the embryogenesis frequency and endogenous putrescine level. It indicated that increase in putrescine content at early stage of differentiation promoted embryogenesis. With the development of somatic embryo, spermidine content reached its the highest level at globular embryo stage, spermine content rose and reached a peak at a later stage of globular embryo development. Furthermore, changes of the putrescine, spermidine and spermine contents during somatic embryogenesis were similar in Valencia calli which had different ploidy levels, but their contents decreased following the increasing of ploidy level. Changes in arginine decarboxylase activity were positively correlated to the polyamine levels, which suggest that the later is a key factor in regulating the polyamine levels during somatic embryogenesis in citrus plants. PMID:15961902

Liu, Hua-Ying; Xiao, Lang-Tao; Lu, Xu-Dong; Hu, Jia-Jin; Wu, Shun; He, Chang-Zheng; Deng, Xiu-Xin

2005-06-01

81

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

82

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

PubMed Central

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

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

2011-01-01

83

Regeneration of pineapple plants via somatic embryogenesis and organogenesis  

Microsoft Academic Search

Summary  We have developed efficient methods for plant regeneration, via both embryogenesis and organogenesis, of Smooth Cayenne pineapple,\\u000a Ananas comosus (L.) Merr. Leaf bases and core (stem) sections of in vitro shoots, produced from culture of crown tip meristem, were used as explants for plant regeneration as follows: (1) Leaf base\\u000a and core section explants cultured on Murashige and Skoog (MS)

E. Firoozabady; Y. Moy

2004-01-01

84

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

PubMed Central

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

2010-01-01

85

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

PubMed Central

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

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

2013-01-01

86

Regeneration of Solanum nigrum by somatic embryogenesis, involving frog egg-like body, a novel structure.  

PubMed

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

87

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

88

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; Samaj, Jozef

2011-01-01

89

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

90

Detection of somaclonal variants in somatic embryogenesis-regenerated plants of Vitis vinifera by flow cytometry and microsatellite markers  

Microsoft Academic Search

Flow cytometry and microsatellite analyses were used to evaluate the trueness-to-type of somatic embryogenesis-regenerated\\u000a plants from six important Spanish grapevine (Vitis vinifera L.) cultivars. Tetraploid plants were regenerated through somatic embryogenesis from all of the cultivars tested with the\\u000a exception of ‘Merenzao’. In addition, an octoploid plant was obtained in the cv. ‘Albariño’, and two mixoploids in ‘Torrontés’.\\u000a The most

María Jesús Prado; Eleazar Rodriguez; Laura Rey; María Victoria González; Conceição Santos; Manuel Rey

2010-01-01

91

Endogenous Abscisic Acid and Indole-3-Acetic Acid and Somatic Embryogenesis in Cultured Leaf Explants of Pennisetum purpureum Schum. 1  

PubMed Central

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 (GA3; >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, Kanniah; Hein, Mich B.; Vasil, Indra K.

1987-01-01

92

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

PubMed

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

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

2013-10-01

93

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

Microsoft Academic Search

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

S. Saxena; V. Dhawan

1999-01-01

94

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

95

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

PubMed

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

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

2012-07-01

96

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

PubMed Central

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

Yang, Jingli; Wu, Songquan; Li, Chenghao

2013-01-01

97

Interspecific hybrids of Cucumis metuliferus × C. anguria obtained through embryo culture and somatic embryogenesis  

Microsoft Academic Search

Interspecific crosses between Cucumis metuliferus Naud. and C. anguria L. were obtained through embryo culture. Embryos in the rabbit-ear to advanced fluke-shaped stages were rescued 34–99 days after pollination. Plants were obtained through direct embryo culture, and through somatic embryogenesis from immature embryos. For direct embryo culture, fluke-shaped embryos were stored in sterile water in darkness for three days at

George Fassuliotis; B. V. Nelson

1988-01-01

98

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

Microsoft Academic Search

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

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

2007-01-01

99

Starch and triacylglycerol metabolism related to somatic embryogenesis in Papaver orientale tissue cultures  

Microsoft Academic Search

During somatic embryogenesis in Papaver orientale tissue cultures a permanent starch accumulation and a transient triacylglycerol accumulation were observed. The degradation of the lipids during plantlet development from embryoids was paralleled by an activity increase of the glyoxylate-cycle enzymes malate synthase (EC 4.1.3.2) and isocitrate lyase (EC 4.1.3.1). Fat accumulation and breakdown was interpreted as a reflection of seed formation

Sayuri Hara; Heinz Falk; Hans Kleinig

1985-01-01

100

Characterisation of a cyclin-dependent kinase ( CDKA ) gene expressed during somatic embryogenesis of coconut palm  

Microsoft Academic Search

The CDKA gene is linked to the cellular control. This gene was isolated from coconut palm (Cocos nucifera L) and a detailed expression analysis was done during somatic embryogenesis. Analysis of the deduced amino acid sequence\\u000a showed the most important residues to be conserved. The highest homology was with Picea abies (96% similarity). Expression of the putative CnCDKA gene steadily

Mayra Montero-Cortés; Francisco Rodríguez-Paredes; Caroline Burgeff; Teresa Pérez-Nuñez; Iván Córdova; Carlos Oropeza; Jean-Luc Verdeil; Luis Sáenz

2010-01-01

101

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

102

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

103

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

Microsoft Academic Search

A reliable genetic transformation protocol via somatic embryogenesis has been developed for the production of fertile, herbicide-resistant\\u000a opium poppy plants. Transformation was mediated by Agrobacterium tumefaciens using the pCAMBIA3301 vector, which harbors the phosphinothricin acetyltransferase (pat) gene driven by a tandem repeat of the cauliflower mosaic virus (CaMV) 35S promoter and the ?-glucuronidase (gus) structural gene driven by a single

Peter J. Facchini; Natalia Loukanina; Vincent Blanche

2008-01-01

104

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

105

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

106

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

107

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

108

Somatic embryogenesis and plant regeneration in Gloriosa L.  

PubMed

Friable callus was initiated from shoot apices of Gloriosa superba L. on basal MS medium supplemented with 2, 4-D (4mg L(-1)) + Kn(5 mg L(-1)) + CH(10 mg L(-1)) + CW(20%). Subculture of callus on the same medium after 4-5 weeks showed induction of large number of somatic embryos, which was confirmed with histological studies. Development of embryoids in plantlet took place when the embryogenic callus was transferred to basal MS medium supplemented with BAP (5 mg L(-1)), CH(50 mg L(-1)) +CW(20%). Roots were developed by subculturing them on to the medium containing Kn or BAP (5 mg L(-1)) and IBA (4 mg L(-1)). Plantlets were successfully transferred to pots containing mixture of soil, sand and farmyard manure (2:1:1). PMID:11831383

Jadhav, S Y; Hegde, B A

2001-09-01

109

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

110

Protocol for Callus Induction and Somatic Embryogenesis in Moso Bamboo  

PubMed Central

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

Wu, Xiao-Li; Gu, Xiao-Ping

2013-01-01

111

Ultrastructural changes and the distribution of arabinogalactan proteins during somatic embryogenesis of banana (Musa spp. AAA cv. 'Yueyoukang 1').  

PubMed

A better understanding of somatic embryogenesis in banana (Musa spp.) may provide a practical way to improve regeneration of banana plants. In this study, we applied scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to visualize the ultrastructural changes during somatic embryogenesis of banana (Musa AAA cv. 'Yueyoukang 1'). We also used histological and immunohistochemical techniques with 16 monoclonal antibodies to study the spatial distribution and cellular/subcellular localization of different arabinogalactan protein (AGP) components of the cell wall during somatic embryogenesis. Histological study with periodic acid-Schiff staining documented diverse embryogenic stages from embryogenic cells (ECs) to the late embryos. SEM revealed a mesh-like structure on the surface of proembryos which represented an early structural marker of somatic embryogenesis. TEM showed that ECs were rich in juvenile mitochondria, endoplasmic reticulum and Golgi stacks. Cells in proembryos and early globular embryos resembled ECs, but they were more vacuolated, showed more regular nuclei and slightly more developed organelles. Immunocytochemical study revealed that the signal of most AGP epitopes was stronger in starch-rich cells when compared with typical ECs. The main AGP component in the extracellular matrix surface network of banana proembryos was the MAC204 epitope. Later, AGP immunolabelling patterns varied with the developmental stages of the embryos. These results about developmental regulation of AGP epitopes along with developmental changes in the ultrastructure of cells are providing new insights into the somatic embryogenesis of banana. PMID:21496030

Pan, Xiao; Yang, Xiao; Lin, Guimei; Zou, Ru; Chen, Houbin; Samaj, Jozef; Xu, Chunxiang

2011-08-01

112

Somatic embryogenesis in Cymbopogon pendulus and evaluation of clonal fidelity of regenerants using ISSR marker  

Microsoft Academic Search

An efficient plant propagation system through somatic embryogenesis was established in Cymbopogon pendulus, an aromatic grass followed by analysis of genetic status of regenerants using ISSR markers. Optimum embryogenic callus induction was observed on MS basal medium supplemented with 13.57?M 2,4-dicholorophenoxyacetic acid (2,4-D) with 8.88?M N6-benzyladenine (BA). Subsequent culturing of embryogenic calli on MS medium containing 4.52?M 2,4-D and 8.88–13.32?M

S. Bhattacharya; T. K. Bandopadhyay; P. D. Ghosh

2010-01-01

113

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

114

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

115

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

PubMed Central

Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somatic embryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F1 plantlets confirmed the presence of the hybrid plantlets. PMID:23235330

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

2012-01-01

116

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

PubMed

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

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

2012-01-01

117

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

118

Identification of expressed sequences in the coffee genome potentially associated with somatic embryogenesis.  

PubMed

Brazil possesses the most modern and productive coffee growing farms in the world, but technological development is desired to cope with the increasing world demand. One way to increase Brazilian coffee growing productivity is wide scale production of clones with superior genotypes, which can be obtained with in vitro propagation technique, or from tissue culture. These procedures can generate thousands of clones. However, the methodologies for in vitro cultivation are genotype-dependent, which leads to an almost empirical development of specific protocols for each species. Therefore, molecular markers linked to the biochemical events of somatic embryogenesis would greatly facilitate the development of such protocols. In this context, sequences potentially involved in embryogenesis processes in the coffee plant were identified in silico from libraries generated by the Brazilian Coffee Genome Project. Through these in silico analyses, we identified 15 EST-contigs related to the embryogenesis process. Among these, 5 EST-contigs (3605, 9850, 13686, 17240, and 17265) could readily be associated with plant embryogenesis. Sequence analysis of EST-contig 3605, 9850, and 17265 revealed similarity to a polygalacturonase, to a cysteine-proteinase, and to an allergenine, respectively. Results also show that EST-contig 17265 sequences presented similarity to an expansin. Finally, analysis of EST-contig 17240 revealed similarity to a protein of unknown function, but it grouped in the similarity dendrogram with the WUSCHEL transcription factor. The data suggest that these EST-contigs are related to the embryogenic process and have potential as molecular markers to increase methodological efficiency in obtaining coffee plant embryogenic materials. PMID:23765976

Silva, A T; Paiva, L V; Andrade, A C; Barduche, D

2013-01-01

119

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

PubMed Central

Many of the regulatory processes occurring during plant embryogenesis are still unknown. Relatively few cells are involved, and they are embedded within maternal tissues, making this developmental phase difficult to study. Somatic embryogenesis is a more accessible system, and many important regulatory genes appear to function similar to zygotic development, making somatic embryogenesis a valuable model for the study of zygotic processes. To better understand the role of the Arabidopsis (Arabidopsis thaliana) MADS factor AGAMOUS-Like15 (AGL15) in the promotion of somatic embryogenesis, direct target genes were identified by chromatin immunoprecipitation-tiling arrays and expression arrays. One potential directly up-regulated target was At5g61590, which encodes a member of the ethylene response factor subfamily B-3 of APETALA2/ETHYLENE RESPONSE FACTOR transcription factors and is related to Medicago truncatula SOMATIC EMBRYO-RELATED FACTOR1 (MtSERF1), which has been shown to be required for somatic embryogenesis in M. truncatula. Here, we report confirmation that At5g61590 is a directly expressed target of AGL15 and that At5g61590 is essential for AGL15’s promotion of somatic embryogenesis. Because At5g61590 is a member of the ETHYLENE RESPONSE FACTOR family, effects of ethylene on somatic embryogenesis were investigated. Precursors to ethylene stimulate somatic embryogenesis, whereas inhibitors of ethylene synthesis or perception reduce somatic embryogenesis. To extend findings to a crop plant, we investigated the effects of ethylene on somatic embryogenesis in soybean (Glycine max). Furthermore, we found that a potential ortholog of AGL15 in soybean (GmAGL15) up-regulates ethylene biosynthesis and response, including direct regulation of soybean orthologs of At5g61590/MtSERF1 named here GmSERF1 and GmSERF2, in concordance with the M. truncatula nomenclature. PMID:23457229

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

2013-01-01

120

A mathematical model for the coreceptors SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE1 and SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE3 in BRASSINOSTEROID INSENSITIVE1-mediated signaling.  

PubMed

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

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

2013-11-01

121

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

PubMed

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

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

2007-11-01

122

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

PubMed

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

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

2014-10-01

123

Plant regeneration through somatic embryogenesis in the forage grass Caucasian bluestem (Bothriochloa caucasica).  

PubMed

Plantlets were regenerated from cultured seed explants of the forage grass Caucasian bluestem [Bothriochloa caucasica (Trin.) C.E. Hubbard] via somatic embryogenesis. Embryogenic callus was produced in four weeks when surface sterilized seeds were cultured on a medium containing MS-salts, B-5 vitamins, 12 mM L-proline, 2% sucrose, 0.8% agar and 5?M 2,4-D. Plantlets were regenerated in 6-8 weeks after culture initiation. Healthy root and shoot systems were produced within three weeks after the plantlets were transferred to a medium lacking 2,4-D. Approximately 95% of the plantlets survived greenhouse acclimation and produced healthy plants and viable seeds. Caucasian bluestem callus cultures exhibit natural resistance to kanamycin. High levels of kanamycin (up to 800 mg/l) did not completely inhibit callus growth. However, the regeneration of healthy-plantlets was completely inhibited by kanamycin even at low levels (50 mg/l). PMID:24227174

Franklin, C I; Trieu, T N; Gonzales, R A

1990-12-01

124

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

PubMed

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

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

2010-04-01

125

Characterization of CsSEF1 gene encoding putative CCCH-type zinc finger protein expressed during cucumber somatic embryogenesis.  

PubMed

Somatic embryos obtained in vitro are a form of vegetative reproduction that can be used in artificial seed technology, as well as a model to study the principles of plant development. In order to isolate the genes involved in somatic embryogenesis of the cucumber (Cucumis sativus L.), we utilized the suppression subtractive hybridization (SSH). One of the obtained sequences was the CsSEF1 clone (Cucumis sativus Somatic Embryogenesis Zinc Finger 1), with a level of expression that sharply increased with the induction of embryogenesis. The full length cDNA of CsSEF1 encodes the putative 307 amino acid long protein containing three zinc finger motifs, two with CCCH and one with the atypical CHCH pattern. The CsSEF1 protein shows significant similarity to other proteins from plants, in which the zinc fingers arrangement and patterns are very similar. Transcripts of CsSEF1 were localized in the apical part of somatic embryos, starting as early as the polarity was visible and in later developmental stages marking the cotyledon primordia and procambium tissues. As a result of transferring an antisense fragment of CsSEF1 into Arabidopsis thaliana abnormalities in zygotic embryos and also in cotyledons and root development were observed. PMID:18778873

Grabowska, Agnieszka; Wisniewska, Anita; Tagashira, Norikazu; Malepszy, Stefan; Filipecki, Marcin

2009-02-15

126

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

127

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

128

Effect of liquid pulses with 6-benzyladenine on the induction of somatic embryogenesis from coffee ( Coffea arabica L.) callus cultures  

Microsoft Academic Search

We investigated the effect of the physical state of the nutrient medium on the induction of somatic embryogenesis on cell\\u000a cultures derived from coffee (Coffea arabica L.). Non-embryogenic callus tissues were pulsed initially with 50 ?M 6-benzyladenine (BA) for 6, 24 or 48 h in half-strength\\u000a liquid Murashige and Skoog (MS) medium. After pretreatment, calli were transferred to agar-solidified half-strength MS medium

Iosif Papanastasiou; Katerina Soukouli; Georgia Moschopoulou; Jane Kahia; Spiridon Kintzios

2008-01-01

129

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

Microsoft Academic Search

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

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

1998-01-01

130

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

Microsoft Academic Search

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

Takeo Saito; Shuji Nishizawa; Shigeo Nishimura

1991-01-01

131

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

Microsoft Academic Search

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

Patricia Gutièrrez pesce; Eddo Rugini

2004-01-01

132

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

133

Somatic embryogenesis and organogenesis of Agave victoriae-reginae : Considerations for its conservation  

Microsoft Academic Search

Agave victoriae-reginae somatic embryos were produced through a callus phase from seedling stem segments cultured on MS medium. The optimal treatment was MS medium with 2.26 µM 2,4-D. Multiple shoot regeneration was induced from axillary buds from stem segments cultured on MS medium with 2.2–4.4 µM BA. Effect of MS and modified MS medium with 50% macronutrient concentration, both containing

Alejandro Martínez-Palacios; M. Pilar Ortega-Larrocea; Víctor M. Chávez; Robert Bye

2003-01-01

134

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

135

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

PubMed Central

Analysis of cDNA-AFLP was used to study the genes expressed in zygotic and somatic embryogenesis of Musa acuminata Colla ssp. malaccensis, and a comparison was made between their differential transcribed fragments (TDFs) and the sequenced genome of the double haploid- (DH-) Pahang of the malaccensis subspecies that is available in the network. A total of 253 transcript-derived fragments (TDFs) were detected with apparent size of 100–4000 bp using 5 pairs of AFLP primers, of which 21 were differentially expressed during the different stages of banana embryogenesis; 15 of the sequences have matched DH-Pahang chromosomes, with 7 of them being homologous to gene sequences encoding either known or putative protein domains of higher plants. Four TDF sequences were located in all Musa chromosomes, while the rest were located in one or two chromosomes. Their putative individual function is briefly reviewed based on published information, and the potential roles of these genes in embryo development are discussed. Thus the availability of the genome of Musa and the information of TDFs sequences presented here opens new possibilities for an in-depth study of the molecular and biochemical research of zygotic and somatic embryogenesis of Musa. PMID:24027442

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

2013-01-01

136

Pollen embryogenesis to induce, detect, and analyze mutants.  

PubMed Central

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. PMID:7460882

Constantin, M J

1981-01-01

137

Somatic embryogenesis and synthetic seed production--a biotechnological approach for true-to-type propagation and in vitro conservation of an ornamental bulbaceous plant Drimiopsis kirkii Baker.  

PubMed

An efficient plant regeneration protocol through indirect somatic embryogenesis pathway via callus had been developed from the leaf explant of an ornamental bulbaceous plant Drimiopsis kirkii. Optimum friable calli were induced on Murashige and Skoog (MS) basal medium supplemented with 3.0 mg/l of 2,4-dichlorophenoxyacetic acid and 1.0 mg/l of ?-naphthalene acetic acid (NAA). On subculturing the callus on MS medium supplemented with 2.5 mg/l of thidiazuron (TDZ), 73.3 % of the cultures responded with 20.4 ± 0.3 somatic embryos (SEs) per 500 mg callus at different stages of development after 6 weeks of culture. The highest response of 86.7 % with 28.3 ± 0.5 embryos per 500 mg callus was observed on MS medium supplemented with 2.5 mg/l TDZ and 1.0 mg/l NAA. SEs were encapsulated in calcium alginate beads for the production of synthetic seeds (SSs) and their storability was investigated. The highest SS germination (93.3 %) was observed in 1.0 % sodium alginate followed by 86.7 % germination with 2.5 % sodium alginate. The SSs were stored at three different temperatures (4, 15, and 24?ºC) up to 6 months. The SSs kept at 15 °C showed 64.4 % germinability even after 4 months of storage. Both nonencapsulated and encapsulated SE-derived plants were successfully transferred to soil with 93.3 and 88.3 % survival rate accordingly. Randomly amplified polymorphic DNA (RAPD) analysis revealed that there were no somaclonal variations among the plants produced via somatic embryogenesis and they are true-to-type to their parental plant. These results confirmed the most reliable methods, which can be further used for genetic transformation studies as well as for mass propagation of ornamental D. kirkii at a commercial level. PMID:24604129

Haque, Sk Moquammel; Ghosh, Biswajit

2014-04-01

138

A carrot G-box binding factor-type basic region/leucine zipper factor DcBZ1 is involved in abscisic acid signal transduction in somatic embryogenesis.  

PubMed

Carrot (Daucus carota) somatic embryogenesis has been extensively used as an experimental system for studying embryogenesis. In maturing zygotic embryos, abscisic acid (ABA) is involved in acquisition of desiccation tolerance and dormancy. On the other hand, somatic embryos contain low levels of endogenous ABA and show desiccation intolerance and lack dormancy, but tolerance and dormancy can be induced by exogenous application of ABA. In ABA-treated carrot embryos, some ABA-inducible genes are expressed. We isolated the Daucus carota bZIP1 (DcBZ1) gene encoding a G-box binding factor-type basic region/leucine zipper (GBF-type bZIP) factor from carrot somatic embryos. The expression of DcBZ1 was detected in embryogenic cells, non-embryogenic cells, somatic embryos, developing seeds, seedlings, and true leaves. Notably, higher expression was detected in embryogenic cells, true leaves, and seedlings. The expression of DcBZ1 increased in seedlings and true leaves after ABA treatment, whereas expression was not affected by differences in light conditions. During the development of zygotic and somatic embryos, increased expression of DcBZ1 was commonly detected in the later phase of development. The recombinant DcBZ1 protein showed specific binding activity to the two ABA-responsive element-like motifs (motif X and motif Y) in the promoter region of the carrot ABA-inducible gene according to results from an electrophoretic mobility shift assay. Our findings suggest that the carrot GBF-type bZIP factor, DcBZ1, is involved in ABA signal transduction in embryogenesis and other vegetative tissues. PMID:18407508

Shiota, Hajime; Ko, Sukmin; Wada, Shinko; Otsu, Claudia Tomiko; Tanaka, Ichiro; Kamada, Hiroshi

2008-01-01

139

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

140

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

141

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

142

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

PubMed

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

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

2012-07-01

143

Genotypic variation and chromosomal location of QTLs for somatic embryogenesis revealed by epidermal layers culture of recombinant inbred lines in the sunflower (Helianthus annuus L.)  

Microsoft Academic Search

The present study was conducted to identify the genetic factors controlling somatic embryogenesis in the sunflower. Two traits,\\u000a the number of embryogenic explants per 40 explants plated (EE\\/40 E) and the number of embryos per 40 explants (E\\/40 E), were\\u000a scored in 74 recombinant inbred lines (RILs) from a cross between ’PAC-2’ and ’RHA-266’. The experiment was designed as a

E. Flores Berrios; A. Sarrafi; F. Fabre; G. Alibert; L. Gentzbittel

2000-01-01

144

Plant regeneration from the root-derived embryonic tissues of Rosa hybrida L. cv. Charming via a combined pathway of somatic embryogenesis and organogenesis  

Microsoft Academic Search

This study describes culture conditions for a plant regeneration system via a combined pathway of somatic embryogenesis and\\u000a organogenesis in root explant cultures of the commercial rose cultivar 'Charming'. Root explants formed white calluses at\\u000a a frequency of 30% after 6 weeks of culture on Schenk and Hildebrandt (SH) medium supplemented with 11 mg l?1 2,4-dichlorophenoxyacetic acid. After 6 weeks of transfer to SH

Suk Weon Kim; Myung Jin Oh; Jang R. Liu

2009-01-01

145

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

Microsoft Academic Search

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

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

2008-01-01

146

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

147

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

148

Somatic embryogenesis on various potato tissues from a range of genotypes and ploidy levels  

Microsoft Academic Search

Somatic embryos (SEs) formed on in vitro-cultured stem internodes, leaves, microtubers and roots of 18 tetraploid potato (Solanum tuberosum L.) cultivars, diploid and monoploid germplasm and three wild Solanum species. A two-step protocol with 6-benzylaminopurine or thidiazuron in the first medium, and zeatin, indoleacetic acid and gibberellic acid in the second medium produced SEs within 14-28 days. SEs developed through

J. E. A. Seabrook; L. K. Douglass

2001-01-01

149

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

Microsoft Academic Search

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

B. Li; D. J. Wolyn

1997-01-01

150

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

151

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

PubMed Central

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

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

2013-01-01

152

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

153

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

154

Somatic embryogenesis, tetraploidy, and variant leaf morphology in transgenic diploid strawberry (Fragaria vesca subspecies vesca ‘Hawaii 4’)  

PubMed Central

Background The diploid (2n = 2x = 14) strawberry model plant Fragaria vesca ssp. vesca ‘Hawaii 4’ was employed for functional analysis of expressed DNA sequences initially identified as being unique to Fragaria and of unknown or poorly understood function. ‘Hawaii 4’ is prominent in strawberry research due to its ease of Agrobacterium-mediated transformation and regenerability, and its status as the source of the first complete strawberry genomic sequence. Our studies of a set of transformants have documented intriguing, construct-associated effects on leaf morphology, and provide important and unexpected insights into the performance of the ‘Hawaii 4’ transformation and regeneration system. Results Following Agrobacterium-mediated transformation of leaf explants with gene constructs carried by Gateway® vectors, plants were regenerated using a modified version of an established ‘Hawaii 4’ protocol. Expanding upon the findings of prior studies, we documented that plantlet regeneration was occurring via a somatic embryogenic rather than an organogenic developmental pathway. Among transformants, several variations in leaf morphology were observed. Unexpectedly, a particular leaf variant type, occurring in ~17% of all regenerants independent of construct type, was found to be attributable to tetraploidy. The tetraploidy-associated alteration in leaf morphology could be differentiated from the leaf morphology of diploid regenerants on the basis of a quantitative ratio of leaf dimensions: B/A, where B is the width of the central leaflet and A is the overall width of the trifoliate leaf. Variant effects on leaf morphology of four different transgenic constructs were also documented, and were in all cases distinguishable from the effects of tetraploidy. Conclusions These results define opportunities to optimize the existing ‘Hawaii 4’ protocol by focusing on treatments that specifically promote somatic embryogenesis. The reported morphological metric and descriptions will guide future transgenic studies using the ‘Hawaii 4’ model system by alerting researchers to the potential occurrence of polyploid regenerants, and to differentiating the effects on leaf morphology due to polyploidy versus transgenic manipulations. Finally, an intriguing spectrum of leaf morphology alterations resulting from manipulation of expressed sequences of uncertain function is documented, providing a foundation for detailed studies of the respective genes and their functional roles. PMID:24418064

2014-01-01

155

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

156

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

157

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

158

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

159

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

160

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

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

2013-01-01

162

The Effects of Exogenous Auxins on Endogenous Indole-3-Acetic Acid Metabolism (The Implications for Carrot Somatic Embryogenesis).  

PubMed Central

The effect of auxin application on auxin metabolism was investigated in excised hypocotyl cultures of carrot (Daucus carota). Concentrations of both free and conjugated indole-3-acetic acid (IAA), [2H4]IAA, 2,4-dichlorophenoxyacetic acid, and naphthaleneacetic acid (NAA) were measured by mass spectroscopy using stable-isotope-labeled internal standards. [13C1]NAA was synthesized for this purpose, thus extending the range of auxins that can be assayed by stable-isotope techniques. 2,4-Dichlorophenoxyacetic acid promoted callus proliferation of the excised hypocotyls, accumulated as the free form in large quantities, and had minor effects on endogenous IAA concentrations. NAA promoted callus proliferation and the resulting callus became organogenic, producing both roots and shoots. NAA was found mostly in the conjugated form and had minor effects on endogenous IAA concentrations. [2H4]IAA had no visible effect on the growth pattern of cultured hypocotyls, possibly because it was rapidly metabolized to form inactive conjugates or possibly because it mediated a decrease in endogenous IAA concentrations by an apparent feedback mechanism. The presence of exogenous auxins did not affect tryptophan labeling of either the endogenous tryptophan or IAA pools. This suggested that exogenous auxins did not alter the IAA biosynthetic pathway, but that synthetic auxins did appear to be necessary to induce callus proliferation, which was essential for excised hypocotyls to gain the competence to form somatic embryos. PMID:12226408

Ribnicky, D. M.; Ilic, N.; Cohen, J. D.; Cooke, T. J.

1996-01-01

163

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

Microsoft Academic Search

The effect of different vitamins and inorganic micronutrients on callus growth and the induction and proliferation of somatic embryos from young mature, fully expanded leaves of chilli pepper (Capsicum annuum L.) was investigated. Explants were cultured on a solid Murashige and Skoog (MS) medium supplemented with 8% (w\\/v) sucrose, 12.9 µM 6-benzyladenine, 9 µM 2,4-dichlorophenoxyacetic acid and 0.5 mg l-1

S. Kintzios; J. B. Drossopoulos; Ch. Lymperopoulos

2001-01-01

164

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

165

Embryogenesis and blastocyst development after somatic cell nuclear transfer in nonhuman primates: overcoming defects caused by meiotic spindle extraction  

Microsoft Academic Search

Therapeutic cloning or nuclear transfer for stem cells (NTSC) seeks to overcome immune rejection through the development of embryonic stem cells (ES cells) derived from cloned blastocysts. The successful derivation of a human embryonic stem cell (hESC) line from blastocysts generated by somatic cell nuclear transfer (SCNT) provides proof-of-principle for “therapeutic cloning,” though immune matching of the differentiated NT-hES remains

Calvin Simerly; Christopher Navara; Sang Hwan Hyun; Byeong Chun Lee; Sung Keun Kang; Saverio Capuano; Gabriella Gosman; Tanja Dominko; Kowit-Yu Chong; Duane Compton; Woo Suk Hwang; Gerald Schatten

2004-01-01

166

Bisphenol A induces otolith malformations during vertebrate embryogenesis  

PubMed Central

Background The plastic monomer and plasticizer bisphenol A (BPA), used for manufacturing polycarbonate plastic and epoxy resins, is produced at over 2.5 million metric tons per year. Concerns have been raised that BPA acts as an endocrine disruptor on both developmental and reproductive processes and a large body of evidence suggests that BPA interferes with estrogen and thyroid hormone signaling. Here, we investigated BPA effects during embryonic development using the zebrafish and Xenopus models. Results We report that BPA exposure leads to severe malformations of the otic vesicle. In zebrafish and in Xenopus embryos, exposure to BPA during the first developmental day resulted in dose-dependent defects in otolith formation. Defects included aggregation, multiplication and occasionally failure to form otoliths. As no effects on otolith development were seen with exposure to micromolar concentrations of thyroid hormone, 17-ß-estradiol or of the estrogen receptor antagonist ICI 182,780 we conclude that the effects of BPA are independent of estrogen receptors or thyroid-hormone receptors. Na+/K+ ATPases are crucial for otolith formation in zebrafish. Pharmacological inhibition of the major Na+/K+ ATPase with ouabain can rescue the BPA-induced otolith phenotype. Conclusions The data suggest that the spectrum of BPA action is wider than previously expected and argue for a systematic survey of the developmental effects of this endocrine disruptor. PMID:21269433

2011-01-01

167

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

Microsoft Academic Search

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

John J. Finer

1987-01-01

168

Cytokinins induce direc somatic embryogenesis of Dendrobium chiengmai pink and subsequent plant regeneration  

Microsoft Academic Search

Summary  Four auxins (2,4-dichlorophenoxyacetic acid [2,4-D], indole-3-acetic acid [IAA], indole-3-butyric acid [IBA], and naphthaleneacetic\\u000a acid [NAA]), and five cytokinins (N\\u000a 6-[2-isopentenyl]-adenine [2iP], N\\u000a 6-benzyladenine [BA], 6-furfurylaminopurine [kinetin], 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea [TDZ], and 6-[4-hydroxy-3-methylbut-2-enylamino]purine\\u000a [zeatin]) were examined for their effects on direct embryo induction from leaf explants of Dendrobium cv. Chiengmai Pink cultured on 1\\/2 Murashige and Skoog (MS) medium. Whether in light or

Hsiao-Hang Chung; Jen-Tsung Chen; Wei-Chin Chang

2005-01-01

169

UNG shapes the specificity of AID-induced somatic hypermutation.  

PubMed

Secondary diversification of antibodies through somatic hypermutation (SHM) and class switch recombination (CSR) is a critical component of the immune response. Activation-induced deaminase (AID) initiates both processes by deaminating cytosine residues in immunoglobulin genes. The resulting U:G mismatch can be processed by alternative pathways to give rise to a mutation (SHM) or a DNA double-strand break (CSR). Central to this processing is the activity of uracil-N-glycosylase (UNG), an enzyme normally involved in error-free base excision repair. We used next generation sequencing to analyze the contribution of UNG to the resolution of AID-induced lesions. Loss- and gain-of-function experiments showed that UNG activity can promote both error-prone and high fidelity repair of U:G lesions. Unexpectedly, the balance between these alternative outcomes was influenced by the sequence context of the deaminated cytosine, with individual hotspots exhibiting higher susceptibility to UNG-triggered error-free or error-prone resolution. These results reveal UNG as a new molecular layer that shapes the specificity of AID-induced mutations and may provide new insights into the role of AID in cancer development. PMID:22665573

Pérez-Durán, Pablo; Belver, Laura; de Yébenes, Virginia G; Delgado, Pilar; Pisano, David G; Ramiro, Almudena R

2012-07-01

170

Current methods for inducing pluripotency in somatic cells.  

PubMed

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

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

2013-05-28

171

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

PubMed Central

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

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

2012-01-01

172

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

173

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

174

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

Microsoft Academic Search

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

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

1991-01-01

175

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

176

LEAFY COTYLEDON2 gene expression and auxin treatment in relation to embryogenic capacity of Arabidopsis somatic cells  

Microsoft Academic Search

The expression pattern of the LEC2 gene during somatic embryogenesis (SE) in Arabidopsis explants (immature zygotic embryos) induced in vitro was followed, using real-time quantitative PCR (qRT-PCR). The analysis\\u000a revealed differential expression of LEC2 transcripts within a 30 days time course of somatic embryo development. A significant auxin-dependent upregulation of the\\u000a LEC2 gene was found to be associated with the induction

Agnieszka Ledwo?; Ma?gorzata D. Gaj

2009-01-01

177

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

Microsoft Academic Search

Induced pluripotency is a new approach to produce embryonic stem-like cells from somatic cells that provides a unique means to understand both pluripotency and lineage assignment. To investigate whether this technology could be applied to endangered species, where the limited availability of gametes makes production and research on embryonic stem cells difficult, we attempted generation of induced pluripotent stem (iPS)

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

178

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

179

Radiation-induced bystander signaling from somatic cells to germ cells in Caenorhabditis elegans.  

PubMed

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

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

2013-09-01

180

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

E-print Network

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

Paris-Sud XI, Université de

181

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; Haggman, Hely

2009-01-01

182

Epithalon peptide induces telomerase activity and telomere elongation in human somatic cells.  

PubMed

Addition of Epithalon peptide in telomerase-negative human fetal fibroblast culture induced expression of the catalytical subunit, enzymatic activity of telomerase, and telomere elongation, which can be due to reactivation of telomerase gene in somatic cells and indicates the possibility of prolonging life span of a cell population and of the whole organism. PMID:12937682

Khavinson, V Kh; Bondarev, I E; Butyugov, A A

2003-06-01

183

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

184

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

Microsoft Academic Search

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

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

1996-01-01

185

[Mammalian DNA methylation and its roles during the induced re-programming of somatic cells].  

PubMed

The technology of induced pluripotent stem cell (iPS) provides the possibility to reverse the terminal differentiated cells to pluripotent stem cells, and is therefore of great importance in both the theoretical research of stem cells and regenerative medicine. However, the efficiency of current induced reprogramming methods is extremely low, and the incomplete reprogramming often happens. It has been reported that some epigenetic memory of the somatic cells exists in these incomplete reprogrammed iPS cells, and DNA methylation, as a relative long-term and stable epigenetic modification, is one of the important factors that influence the efficiency of reprogramming and differentiative capacity of iPS cells. Mammalian DNA methylation, which normally appears on the CpG sites, occurs on the fifth carbon atom of the cytosine ring. DNA methylation can modulate the expression of somatic cell specific genes, and pluripotent genes; hence, it plays important roles in the processes of mammalian gene regulation, embryonic development and cell reprogramming. In addition, it has also been found that abnormal DNA methylation may lead to the disorder of genetic imprinting and the inactivation of X chromosome in iPS cells. Therefore, in order to provide a concise guidance of DNA methylation studies in iPS, we mainly review the mechanism, the distribution features of DNA methylation, and its roles in induced reprogramming of somatic cells. PMID:24846992

Hongwei, Song; Tiezhu, An; Shanhua, Piao; Chunsheng, Wang

2014-05-01

186

Explants of Ri-transformed hairy roots of spinach can develop embryogenic calli in the absence of gibberellic acid, an essential growth regulator for induction of embryogenesis from non-transformed roots  

Microsoft Academic Search

Hairy roots of spinach (Spinacia oleracea L.) were obtained by inoculation of cotyledon explants with wild-type Agrobacterium rhizogenes A13. Integration of the transfer DNA (T-DNA) of a root-inducing (Ri) plasmid of A. rhizogenes into the plant DNA was confirmed by the polymerase chain reaction. Somatic embryogenesis from explants of hairy roots were induced even when the callus-induction (CI) medium did

Takuma Ishizaki; Yoichiro Hoshino; Kiyoshi Masuda; Katsuji Oosawa

2002-01-01

187

Valproate-induced teratogenesis in Japanese rice fish (Oryzias latipes) embryogenesis.  

PubMed

Fertilized eggs of Japanese rice fish (medaka) at three developmental stages (Iwamatsu stages 4-30) were exposed to waterborne valproic acid (VPA) (0-80 mM) in hatching solution for 48 h. The amount of valproate to cause 50% mortality (IC(50)) is found to be developmental stage-specific. The embryos were more sensitive to valproate at early stages of development (Iwamatsu stages 4-10) than in the embryos in late stages (Iwamatsu stages 17-30). Valproate exposed embryos have microcephaly and disrupted cardiovasculature with delayed vessel circulation, thrombus formation, and slow heart rate. The hatching efficiency is also reduced by valproate exposure due to developmental delay. The mRNA analysis of nine genes belong to oxidative stress (catalase, gsr, gst), neurogenesis (iro3, wnt1, shh, otx2, nlgn3b) and cell cycle regulation (ccna2) have been done. It was observed that the genes belong to oxidative stress remained unaltered after valproate exposure. However, some of the genes belong to neurogenesis (wnt1,shh, otx2 and nlgn3b) and cell cycle (ccna2) showed developmental stage-specific alteration after valproate exposure. This study indicates that valproate is able to induce some of the phenotypic features which are analogous to human fetal valproate syndrome (FVS). Modulation of genes expressed in neural tissues indicates that this fish can be used to analyze the mechanisms of many neurobehavioral disorders like Autism spectrum disorder (ASD) in human. PMID:22249148

Wu, Mengmeng; Khan, Ikhlas A; Dasmahapatra, Asok K

2012-04-01

188

Transient acid treatment cannot induce neonatal somatic cells to become pluripotent stem cells  

PubMed Central

Currently, there are genetic- and chemical-based methods for producing pluripotent stem cells from somatic cells, but all of them are extremely inefficient.  However, a simple and efficient technique has recently been reported by Obokata et al (2014a, b) that creates pluripotent stem cells through acid-based treatment of somatic cells.  These cells were named stimulus-triggered acquisition of pluripotency (STAP) stem cells. This would be a major game changer in regenerative medicine if the results could be independently replicated. Hence, we isolated CD45 + splenocytes from five-day-old Oct4-GFP mice and treated the cells with acidified (pH 5.7) Hank’s Balanced Salt Solution (HBSS) for 25 min, using the methods described by Obokata et al 2014c. However, we found that this method did not induce the splenocytes to express the stem cell marker Oct4-GFP when observed under a confocal microscope three to six days after acid treatment. qPCR analysis also confirmed that acid treatment did not induce the splenocytes to express the stemness markers Oct4, Sox2 and Nanog.  In addition, we obtained similar results from acid-treated Oct4-GFP lung fibroblasts. In summary, we have not been able to produce STAP stem cells from neonatal splenocytes or lung fibroblasts using the acid-based treatment reported by Obokata et al (2014a, b, c). PMID:25075303

Tang, Mei Kuen; Lo, Lok Man; Shi, Wen Ting; Yao, Yao; Lee, Henry Siu Sum; Lee, Kenneth Ka Ho

2014-01-01

189

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

PubMed Central

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

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

2009-01-01

190

Identification and immunogold localization of a novel bromegrass (Bromus inermis Leyss) peroxisome channel protein induced by ABA, cold and drought stresses, and late embryogenesis.  

PubMed

A cDNA (BG-15) was isolated through differential screening of a cDNA library made from an ABA-treated bromegrass (Bromus inermis Leyss) suspension cell culture. The 819 bp pair cDNA encoded a 174 amino acid polypeptide with a calculated molecular mass of 18.08 kD and isolectric point of 7.50. The deduced amino acid sequences for the cDNA were 29.5% and 32.6% homologous to the known amino acid-selective channel proteins of the chloroplastic outer membrane in pea and barley, but were highly homologous (55.6% to 83.2%) to the putative membrane channel proteins from rice and Arabidopsis. Immunogold localization demonstrated that the channel protein encoded by this cDNA was present on the peroxisome membrane. High stringency southern analysis revealed that 1 to 2 copies of the peroxisomal channel protein (PCP) genes were present in the bromegrass genome. Northern and Western blots revealed that the PCP gene was responsive to both cold and drought stresses, and was rapidly induced by ABA (75 microM). The transcript of the PCP gene also accumulated during late embryogenesis, but declined rapidly during germination. Data taken together, responsiveness of the PCP to cold and drought stresses, and accumulation during late embryogenesis suggest this novel peroxisomal channel protein is associated with sugar and fatty acid metabolism through fatty acid import or succinate export from peroxisome during desiccation tolerance and energy metabolism. PMID:16226403

Wu, Guohai; Robertson, Albert J; Zheng, Ping; Liu, Xunjia; Gusta, Lawrence V

2005-12-19

191

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

PubMed Central

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

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

2014-01-01

192

Somatic Hypermutation Is Limited by CRM1-dependent Nuclear Export of Activation-induced Deaminase  

PubMed Central

Somatic hypermutation (SHM) and class switch recombination (CSR) are initiated in activated B lymphocytes by activation-induced deaminase (AID). AID is thought to make lesions in DNA by deaminating cytidine residues in single-stranded DNA exposed by RNA polymerase during transcription. Although this must occur in the nucleus, AID is found primarily in the cytoplasm. Here we show that AID is actively excluded from the nucleus by an exportin CRM1-dependent pathway. The AID nuclear export signal (NES) is found at the carboxyl terminus of AID in a region that overlaps a sequence required for CSR but not SHM. We find that AID lacking a functional NES causes more hypermutation of a nonphysiologic target gene in transfected fibroblasts. However, the NES does not impact on the rate of mutation of immunoglobulin genes in B lymphocytes, suggesting that the AID NES does not limit AID activity in these cells. PMID:15117971

McBride, Kevin M.; Barreto, Vasco; Ramiro, Almudena R.; Stavropoulos, Pete; Nussenzweig, Michel C.

2004-01-01

193

Somatic hypermutation is limited by CRM1-dependent nuclear export of activation-induced deaminase.  

PubMed

Somatic hypermutation (SHM) and class switch recombination (CSR) are initiated in activated B lymphocytes by activation-induced deaminase (AID). AID is thought to make lesions in DNA by deaminating cytidine residues in single-stranded DNA exposed by RNA polymerase during transcription. Although this must occur in the nucleus, AID is found primarily in the cytoplasm. Here we show that AID is actively excluded from the nucleus by an exportin CRM1-dependent pathway. The AID nuclear export signal (NES) is found at the carboxyl terminus of AID in a region that overlaps a sequence required for CSR but not SHM. We find that AID lacking a functional NES causes more hypermutation of a nonphysiologic target gene in transfected fibroblasts. However, the NES does not impact on the rate of mutation of immunoglobulin genes in B lymphocytes, suggesting that the AID NES does not limit AID activity in these cells. PMID:15117971

McBride, Kevin M; Barreto, Vasco; Ramiro, Almudena R; Stavropoulos, Pete; Nussenzweig, Michel C

2004-05-01

194

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

PubMed

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

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

2014-01-01

195

Induction of somatic embryos on in vitro cultured zygotic embryos of spring Brassica napus  

Microsoft Academic Search

Mature and immature zygotic embryos of three Brassica napus doubled haploid lines were examined for their ability to produce somatic embryos. Seedlings from mature seeds did not produce somatic embryos in all of the tested media. Induction of somatic embryogenesis directly from immature seeds of doubled haploid lines was obtained on plant growth regulator-free medium. Th ere was no callus

Natalija Burbulis; Ramune Kupriene

196

Somatic mutations in stilbene estrogen-induced Syrian hamster kidney tumors identified by DNA fingerprinting  

PubMed Central

Kidney tumors from stilbene estrogen (diethylstilbestrol)-treated Syrian hamsters were screened for somatic genetic alterations by Random Amplified Polymorphic DNA-polymerase chain-reaction (RAPD-PCR) fingerprinting. Fingerprints from tumor tissue were generated by single arbitrary primers and compared with fingerprints for normal tissue from the same animal, as well as normal and tumor tissues from different animals. Sixty one of the arbitrary primers amplified 365 loci that contain approximately 476 kbp of the hamster genome. Among these amplified DNA fragments, 44 loci exhibited either qualitative or quantitative differences between the tumor tissues and normal kidney tissues. RAPD-PCR loci showing decreased and increased intensities in tumor tissue DNA relative to control DNA indicate that loci have undergone allelic losses and gains, respectively, in the stilbene estrogen-induced tumor cell genome. The presence or absence of the amplified DNA fragments indicate homozygous insertions or deletions in the kidney tumor DNA compared to the age-matched normal kidney tissue DNA. Seven of 44 mutated loci also were present in the kidney tissues adjacent to tumors (free of macroscopic tumors). The presence of mutated loci in uninvolved (non-tumor) surrounding tissue adjacent to tumors from stilbene estrogen-treated hamsters suggests that these mutations occurred in the early stages of carcinogenesis. The cloning and sequencing of RAPD amplified loci revealed that one mutated locus had significant sequence similarity with the hamster Cyp1A1 gene. The results show the ability of RAPD-PCR to detect and isolate, in a single step, DNA sequences representing genetic alterations in stilbene estrogen-induced cancer cells, including losses of heterozygosity, and homozygous deletion and insertion mutations. RAPD-PCR provides an alternative molecular approach for studying cancer cytogenetics in stilbene estrogen-induced tumors in humans and experimental models. Although the exact functional importance of mutated loci is unknown, this study indicates that these altered loci may participate during tumor progression in the kidney. PMID:15003126

Singh, Kamaleshwar P; Roy, Deodutta

2004-01-01

197

Concise review: generation of neurons from somatic cells of healthy individuals and neurological patients through induced pluripotency or direct conversion.  

PubMed

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

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

2014-11-01

198

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

PubMed

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

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

2013-03-01

199

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

PubMed

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

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

2012-01-01

200

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

Microsoft Academic Search

The efficiency of cloning by somatic cell nuclear transfer (SCNT) is poor in livestock with w5% of transferred cloned embryos developing to term. SCNT is associated with gross placental structural abnormalities. We aimed to identify defects in placental histologyand gene expressionin failing ovine cloned pregnanciesto better understand why so many clones generated by SCNT die in utero. Placentomes from SCNT

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

2007-01-01

201

Review: Placental perturbations induce the developmental abnormalities often observed in bovine somatic cell nuclear transfer  

Microsoft Academic Search

Since the first success in cloning sheep, the production of viable animals by somatic cell nuclear transfer (SCNT) has developed significantly. Cattle are by far the most successfully cloned species but, despite this, the technique is still associated with a high incidence of pregnancy failure and accompanying placental and fetal pathologies. Pre- and early post-implantation losses can affect up to

P. Chavatte-Palmer; S. Camous; H. Jammes; N. Le Cleac’h; M. Guillomot; R. S. F. Lee

202

Xist repression shows time-dependent effects on the reprogramming of female somatic cells to induced pluripotent stem cells.  

PubMed

Although the reactivation of silenced X chromosomes has been observed as part of the process of reprogramming female somatic cells into induced pluripotent stem cells (iPSCs), it remains unknown whether repression of the X-inactive specific transcript (Xist) can greatly enhance female iPSC induction similar to that observed in somatic cell nuclear transfer studies. In this study, we discovered that the repression of Xist plays opposite roles in the early and late phases of female iPSCs induction. Our results demonstrate that the downregulation of Xist by an isopropyl ?-d-1-thiogalactopyranoside (IPTG)-inducible short hairpin RNA (shRNA) system can greatly impair the mesenchymal-to-epithelial transition (MET) in the early phase of iPSC induction but can significantly promote the transition of pre-iPSCs to iPSCs in the late phase. Furthermore, we demonstrate that although the knockdown of Xist did not affect the H3K27me3 modification on the X chromosome, macroH2A was released from the inactivated X chromosome (Xi). This enables the X chromosome silencing to be a reversible event. Moreover, we demonstrate that the supplementation of vitamin C (Vc) can augment and stabilize the reversible X chromosome by preventing the relocalization of macroH2A to the Xi. Therefore, our study reveals an opposite role of Xist repression in the early and late stages of reprogramming female somatic cells to pluripotency and demonstrates that the release of macroH2A by Xist repression enables the transition from pre-iPSCs to iPSCs. Stem Cells 2014;32:2642-2656. PMID:24965076

Chen, Qi; Gao, Shuai; He, Wenteng; Kou, Xiaochen; Zhao, Yanhong; Wang, Hong; Gao, Shaorong

2014-10-01

203

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

Microsoft Academic Search

Treatment of pre-activated oocytes with demecolcine (DEM) has been shown to induce the extrusion of all oocyte chromosomes within the second polar body (PB2). However, induced enucleation (IE) rates are generally low and the competence of these cytoplasts to support embryonic development following somatic cell nuclear transfer (SCNT) is impaired. Here, we explored whether short treatments with DEM or another

Nuno Costa-Borges; Maria Teresa Paramio; Josep Santaló; Elena Ibáñez

2011-01-01

204

Distribution of poly(A)-containing RNA during normal pollen development and during induced pollen embryogenesis in Hyoscyamus niger  

Microsoft Academic Search

The distribution of poly(A)-containing RNA (poly(A)+RNA) in pollen grains of Hyoscyamus niger during normal gametophytic development and embryogenic development induced by culture of anther segments was followed by in situ hybridization with (3H)- polyuridylic acid as a probe . No binding of the isotope occurred in pollen grains during the uninucleate phase of their development . Although (3H)polyuridylic acid binding

V. Raghavan

1981-01-01

205

Evaluation of the Effects of STZ-Induced Diabetes on In Vitro Fertilization and Early Embryogenesis Processes  

PubMed Central

The aim of this study was to investigate the effects of experimentally induced diabetes on (a) germ cells, (b) in vitro fertilization (IVF) success rate, and (c) gap junction and cell adhesion molecule gene and protein expressions during the early blastocyst period. Germ cells were obtained from healthy and diabetic rats, analyzed for number, motility, and morphology, and used for IVF. After reaching the early blastocyst stage, the expressions of genes encoding gap junction proteins and cell adhesion molecules were analyzed by quantitative RT-PCR. Histomorphologically and immunohistochemically analyses were also performed. Diabetes significantly affected sperm number and motility and the development of oocytes. Gene expressions of ?-catenin and connexin family members and protein expressions of E-cadherin and connexin-43 significantly decreased in groups including germ cells isolated from diabetic rats. Connective tissue growth factor expression increased in groups that included sperm cells isolated from diabetic male rats, whereas mucin-1 expression increased in the group that included oocytes isolated from diabetic female rats paired with sperm cells isolated from healthy male rats. In summary, experimentally induced diabetes was found to influence gap junctions, cell adhesion molecules, and associated proteins which all have important roles in germ cell maturation, fertilization, and development. PMID:23671879

Aktug, Huseyin; Uysal, Aysegul; Oltulu, Fatih; Yavasoglu, Altug; Akarca, Saadet Ozen; Kosova, Buket

2013-01-01

206

Evaluation of the Effects of STZ-Induced Diabetes on In Vitro Fertilization and Early Embryogenesis Processes.  

PubMed

The aim of this study was to investigate the effects of experimentally induced diabetes on (a) germ cells, (b) in vitro fertilization (IVF) success rate, and (c) gap junction and cell adhesion molecule gene and protein expressions during the early blastocyst period. Germ cells were obtained from healthy and diabetic rats, analyzed for number, motility, and morphology, and used for IVF. After reaching the early blastocyst stage, the expressions of genes encoding gap junction proteins and cell adhesion molecules were analyzed by quantitative RT-PCR. Histomorphologically and immunohistochemically analyses were also performed. Diabetes significantly affected sperm number and motility and the development of oocytes. Gene expressions of ? -catenin and connexin family members and protein expressions of E-cadherin and connexin-43 significantly decreased in groups including germ cells isolated from diabetic rats. Connective tissue growth factor expression increased in groups that included sperm cells isolated from diabetic male rats, whereas mucin-1 expression increased in the group that included oocytes isolated from diabetic female rats paired with sperm cells isolated from healthy male rats. In summary, experimentally induced diabetes was found to influence gap junctions, cell adhesion molecules, and associated proteins which all have important roles in germ cell maturation, fertilization, and development. PMID:23671879

Aktu?, Hüseyin; Bozok Çetinta?, Vildan; Uysal, Ay?egül; Oltulu, Fatih; Yava?o?lu, Altu?; Akarca, Saadet Özen; Kosova, Buket

2013-01-01

207

Mitochondrial Physiology and Gene Expression Analyses Reveal Metabolic and Translational Dysregulation in Oocyte-Induced Somatic Nuclear Reprogramming  

PubMed Central

While reprogramming a foreign nucleus after somatic cell nuclear transfer (SCNT), the enucleated oocyte (ooplasm) must signal that biomass and cellular requirements changed compared to the nucleus donor cell. Using cells expressing nuclear-encoded but mitochondria-targeted EGFP, a strategy was developed to directly distinguish maternal and embryonic products, testing ooplasm demands on transcriptional and post-transcriptional activity during reprogramming. Specifically, we compared transcript and protein levels for EGFP and other products in pre-implantation SCNT embryos, side-by-side to fertilized controls (embryos produced from the same oocyte pool, by intracytoplasmic injection of sperm containing the EGFP transgene). We observed that while EGFP transcript abundance is not different, protein levels are significantly lower in SCNT compared to fertilized blastocysts. This was not observed for Gapdh and Actb, whose protein reflected mRNA. This transcript-protein relationship indicates that the somatic nucleus can keep up with ooplasm transcript demands, whilst transcription and translation mismatch occurs after SCNT for certain mRNAs. We further detected metabolic disturbances after SCNT, suggesting a place among forces regulating post-transcriptional changes during reprogramming. Our observations ascribe oocyte-induced reprogramming with previously unsuspected regulatory dimensions, in that presence of functional proteins may no longer be inferred from mRNA, but rather depend on post-transcriptional regulation possibly modulated through metabolism. PMID:22693623

Esteves, Telma C.; Psathaki, Olympia E.; Pfeiffer, Martin J.; Balbach, Sebastian T.; Zeuschner, Dagmar; Shitara, Hiroshi; Yonekawa, Hiromichi; Siatkowski, Marcin; Fuellen, Georg; Boiani, Michele

2012-01-01

208

Embryogenesis in hydra.  

PubMed

Embryogenesis in hydra includes a variable period of dormancy; and this period, as well as subsequent stages through hatching, takes place within a thick cuticle that hinders observation. Thus, although the early stages of development have been well-characterized qualitatively, the middle and later stages are only poorly understood. Here, we provide a detailed description of the stages of embryogenesis, including the time required to traverse each of the stages, and the changes that occur in the type and number of cells throughout the stages. The events of cleavage and gastrulation occur within the first 48 h. Cleavage is holoblastic and unipolar and leads to a single-layered coeloblastula. Gastrulation occurs by ingression and is followed by the deposition of the thick cuticle. Thereafter, during the variable period of dormancy ranging from 2-24 weeks, little occurs; the important events are the conversion of the outer layer into an ectoderm and the appearance of the interstitial cell lineage. During the last 2 days before hatching, the endoderm and gastric cavity form, while stem cells of the interstitial cell lineage proliferate and differentiate into neurons, nematocytes, and secretory cells. Finally, the cuticle cracks, and the hatchling enlarges and emerges from the cuticle as a functional animal. The formation of the gastric cavity and the hatching of the embryo are both explicable in terms of the osmotic behavior of the animal and the hydrostatic forces generated by this behavior. Characteristics of development that are common to hydra and triploblastic phyla are presented. PMID:9212444

Martin, V J; Littlefield, C L; Archer, W E; Bode, H R

1997-06-01

209

Distribution of poly(A)-containing RNA during normal pollen development and during induced pollen embryogenesis in Hyoscyamus niger.  

PubMed

The distribution of poly(A)-containing RNA [poly(A)+RNA] in pollen grains of Hyoscyamus niger during normal gametophytic development and embryogenic development induced by culture of anther segments was followed by in situ hybridization with [3H]-polyuridylic acid as a probe. No binding of the isotope occurred in pollen grains during the uninucleate phase of their development. Although [3H]polyuridylic acid binding sites were present in the generative and vegetative cells of maturing pollen grains, they almost completely disappeared from mature grains ready to germinate. During pollen germination, poly(A)+RNA formation was transient and was due to the activity of the generative nucleus, whereas the vegetative nucleus and the sperm cells failed to interact with the applied probe. In cultured anther segments, moderate amounts of poly(A)+RNA were detected in the uninucleate, nonvacuolate, embryogenically determined pollen grains. Poly(A)+RNA accumulation in these grains was sensitive to actinomycin D, suggesting that it represents newly transcribed mRNA. After the first haploid mitosis in the embryogenically determined pollen grains, only those grains in which the generative nucleus alone or along with the vegetative nucleus accumulated poly(A)+RNA in the surrounding cytoplasm were found to divide in the embryogenic pathway. Overall, the results suggest that, in contrast to normal gametophytic development, embryogenic development in the uninucleate pollen grains of cultured anther segments of H. niger is due to the transcriptional activation of an informational type of RNA. Subsequent divisions in the potentially embryogenic binucleate pollen grains appeared to be mediated by the continued synthesis of mRNA either in the generative nucleus or in both the generative and vegetative nuclei. PMID:6166618

Raghavan, V

1981-06-01

210

Expression of human AID in yeast induces mutations in context similar to the context of somatic hypermutation at GC pairs in immunoglobulin genes  

Microsoft Academic Search

BACKGROUND: Antibody genes are diversified by somatic hypermutation (SHM), gene conversion and class-switch recombination. All three processes are initiated by the activation-induced deaminase (AID). According to a DNA deamination model of SHM, AID converts cytosine to uracil in DNA sequences. The initial deamination of cytosine leads to mutation and recombination in pathways involving replication, DNA mismatch repair and possibly base

Vladimir I Mayorov; Igor B Rogozin; Linda R Adkison; Christin Frahm; Thomas A Kunkel; Youri I Pavlov

2005-01-01

211

Somatization disorder  

MedlinePLUS

Greenberg DB, Braun IM, Cassem NH. Functional somatic symptoms and somatoform disorders. In: Stern TA, Rosenbaum JF, Fava M, Biederman J, Rauch SL, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry . 1st ...

212

Regulation of Medicago sativa L. somatic embryos regeneration by gibberellin A 3 and abscisic acid in relation to starch content and ?-amylase activity  

Microsoft Academic Search

Somatic embryo quality is an important factor decisive for the efficiency of somatic embryogenesis. Addition gibberellic acid (GA3) at a concentration of 1 ?M to germination medium improved the regeneration of alfalfa somatic embryos. Inhibitory effect of ancymidol, an inhibitor of gibberellin biosynthesis, on germination and conversion may indicate that those processes require endogenous GAs. Since fluridone, an ABA biosynthetic inhibitor,

Ewa K?pczy?ska; Sylwia Zieli?ska

2006-01-01

213

CHAPTER 1. GENE EXPRESSION PATTERNS DURING SOMATIC EMBRYO DEVELOPMENT AND  

E-print Network

expression patterns were profiled during somatic embryogenesis in a regeneration- proficient maize hybrid line, Hi II, in an effort to identify genes that might be used as developmental markers or targets to optimize regeneration steps for recovering maize plants from tissue culture. Gene expression profiles were

Carriquiry, Alicia

214

Transcriptional changes of antioxidant responses, hormone signalling and developmental processes evoked by the Brassica napus SHOOTMERISTEMLESS during in vitro embryogenesis.  

PubMed

Previous work showed that alterations in Brassica napus (Bn) SHOOTMERISTEMLESS (BnSTM) expression levels influence microspore-derived embryogenesis in B. napus. While over-expression of BnSTM increased microspore-derived embryo (MDE) yield and quality, down-regulation of BnSTM repressed embryo formation [16]. Transcriptional analyses were conducted to investigate the molecular mechanisms underpinning these responses. The induction of BnSTM resulted in a heavy transcriptional activation of genes involved in antioxidant responses, hormone signalling and developmental processes. Several antioxidant enzymes, including catalases, superoxide dismutases, and components of the Halliwell-Asada cycle were induced in embryos ectopically expressing BnSTM and contributed to the removal of reactive oxygen species (ROS). These changes were accompanied by elevated levels of ascorbate and glutathione, which have been shown to promote embryonic growth and development. Induction or repression of BnSTM altered the early cytokinin response, whereas late responses, modulated by Type-A Arabidopsis response regulators (ARRs), were induced in MDEs over-expressing BnSTM. Major differences between transgenic MDEs were also observed in the expression pattern of several auxin transporters and key developmental factors required for normal embryogenesis. While some of these factors, BABYBOOM1 (BBM1) and SOMATIC EMBRYOGENESIS RECEPTOR KINASE (SERK), play a key role during early embryogeny, others, CYP78A5, LEAFY COTYLEDON1 and 2 (LEC1 and LEC2), as well as WOX2 and 9, are required for proper embryo development. Collectively these results demonstrate the involvement of BnSTM in novel developmental processes which can be utilized to enhance in vitro embryogenesis. PMID:22878158

Elhiti, Mohamed; Yang, Cunchun; Belmonte, Mark F; Gulden, Robert H; Stasolla, Claudio

2012-09-01

215

Relationship between production of carrot somatic embryos and dissolved oxygen concentration in liquid culture  

Microsoft Academic Search

To evaluate the relationship between somatic embryogenesis and dissolved oxygen concentration, somatic embryo cultures of\\u000a carrot (Daucus carota L.) were cultured under various dissolved oxygen concentration levels (bubble free aeration with 4%,\\u000a 7%, 20%, 30%, and 40% oxygen in flasks). The system used allows dissolved oxygen concentration control without bubble aeration\\u000a or mixing speed modification. The total number of somatic

Teruaki Shimazu; Kenji Kurata

1999-01-01

216

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

PubMed

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

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

2014-02-01

217

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

PubMed Central

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

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

2014-01-01

218

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

Microsoft Academic Search

Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order\\u000a to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed\\u000a at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction\\u000a media were tested with varying concentrations

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

2006-01-01

219

Somatic embryogenesis, maturation and DNA transfer in Pinus  

E-print Network

') into intact conifer cells. Use of micropro)ectile- mediated DNA transfer has been reported for embryogenic cells of Picea glauca (Ellis et aL 1991; 1993), P. abies (Newton et al. 1992; Yibrah and Clapham 1990), P. mariana (Duchesne and Charest 1991... lambertiana Lamb. ) (Gupta and Durzan 1986b), loblolly pine (Pinus taeda L. ) (Becwar et al. 1990; Gupta and Durzan 1987a), white spruce (Picea glauca (Moench) Voss) (Hakman and Fowke 1987a), and black spruce (Picea mariana (Mill. ) B. S. P. ) (Hakman...

Marek, Kimberly Ann

2012-06-07

220

5-Nitro-5'hydroxy-indirubin-3'oxime Is a Novel Inducer of Somatic Cell Transdifferentiation.  

PubMed

Patient-derived cell transplantation is an attractive therapy for regenerative medicine. However, this requires effective strategies to reliably differentiate patient cells into clinically useful cell types. Herein, we report the discovery that 5-nitro-5'hydroxy-indirubin-3'oxime (5'-HNIO) is a novel inducer of cell transdifferentiation. 5'-HNIO induced muscle transdifferentiation into adipogenic and osteogenic cells. 5'-HNIO was shown to inhibit aurora kinase A, which is a known cell fate regulator. 5'-HNIO produced a favorable level of transdifferentiation compared to other aurora kinase inhibitors and induced transdifferentiation across cell lineage boundaries. Significantly, 5'-HNIO treatment produced direct transdifferentiation without up-regulating potentially oncogenic induced pluripotent stem cell (iPSC) reprogramming factors. Thus, our results demonstrate that 5'-HNIO is an attractive molecular tool for cell transdifferentiation and cell fate research. PMID:25363410

Jung, Da-Woon; Hong, Young J; Kim, Soo-Yeon; Kim, Woong-Hee; Seo, Shinae; Lee, Jung-Eun; Shen, Haihong; Kim, Yong-Chul; Williams, Darren R

2014-11-01

221

HoxC4 binds to the promoter of the cytidine deaminase AID gene to induce AID expression, class-switch DNA recombination and somatic hypermutation  

Microsoft Academic Search

The cytidine deaminase AID (encoded by Aicda in mice and AICDA in humans) is critical for immunoglobulin class-switch recombination (CSR) and somatic hypermutation (SHM). Here we show that AID expression was induced by the HoxC4 homeodomain transcription factor, which bound to a highly conserved HoxC4-Oct site in the Aicda or AICDA promoter. This site functioned in synergy with a conserved

Seok-Rae Park; Hong Zan; Zsuzsanna Pal; Jinsong Zhang; Ahmed Al-Qahtani; Egest J Pone; Zhenming Xu; Thach Mai; Paolo Casali

2009-01-01

222

Analysis of potential radiation-induced genetic and somatic effects to man from milling of uranium  

SciTech Connect

Potential mortality from natural causes and from radiation exposure conditions typical of those in the vicinity of uranium mills in the western USA was calculated. The exposure conditions were those assumed to exist in the vicinity of a hypothetical model mill. Dose rates to organs at risk were calculated as a function of time using the Uranium Dispersion and Dosimetry Code (Momeni et al. 1979). The changes in population size, birth rates, and radiation-induced and natural mortalities were calculated using the PRIM code (Momeni 1983). The population of the region within a radius of 80 km from the model mill is projected to increase from 57 428 to 75 638.6 during the 85 years of this analysis. Within the same period, the average birth rates for five-year periods increase from 5067.8 to 7436.1. The cumulative deaths within the five-year periods increase from 724 and 3501.8 from spontaneously induced neoplasms and all causes, respectively, to 1538.2 and 6718.2. In comparison to natural causes, radiation-induced mortality is negligible. The highest rate of death from radiation in any five-year period is only 0.2, compared with 1538.2 deaths attributable to spontaneous incidence. The total radiation-induced genetic disorders were much less than unity for the 85-year period of analysis, in contrast with the 10.7% natural incidence of these disorders.

Momeni, M.H.

1984-01-01

223

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

E-print Network

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

Lander, Eric S.

224

Fishery-Induced Selection for Slow Somatic Growth in European Eel  

PubMed Central

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

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

2012-01-01

225

Embryogenesis and plant regeneration from tissue culture of Canada wildrye, Elymus canadensis L  

Microsoft Academic Search

Somatic embryogenesis and plant regeneration of Canada wildrye (Elymus canadensis L.) from tissue culture was investigated by culturing immature embryos and inflorescences on MS medium containing 2 mg\\/l 2,4-D. The optimum size of explants for maximum embryogenic callus formation was 1.0 to 1.5 mm for embryos and 4 to 6 cm for inflorescences. Plant regeneration from the subcultured embryogenic callus

C. H. Park; P. D. Walton

1989-01-01

226

Anisotropic growth shapes intestinal tissues during embryogenesis.  

PubMed

Embryogenesis offers a real laboratory for pattern formation, buckling, and postbuckling induced by growth of soft tissues. Each part of our body is structured in multiple adjacent layers: the skin, the brain, and the interior of organs. Each layer has a complex biological composition presenting different elasticity. Generated during fetal life, these layers will experience growth and remodeling in the early postfertilization stages. Here, we focus on a herringbone pattern occurring in fetal intestinal tissues. Common to many mammalians, this instability is a precursor of the villi, finger-like projections into the lumen. For avians (chicks' and turkeys' embryos), it has been shown that, a few days after fertilization, the mucosal epithelium of the duodenum is smooth, and then folds emerge, which present 2 d later a pronounced zigzag instability. Many debates and biological studies are devoted to this specific morphology, which regulates the cell renewal in the intestine. After reviewing experimental results about duodenum morphogenesis, we show that a model based on simplified hypothesis for the growth of the mesenchyme can explain buckling and postbuckling instabilities. Being completely analytical, it is based on biaxial compressive stresses due to differential growth between layers and it predicts quantitatively the morphological changes. The growth anisotropy increasing with time, the competition between folds and zigzags, is proved to occur as a secondary instability. The model is compared with available experimental data on chick's duodenum and can be applied to other intestinal tissues, the zigzag being a common and spectacular microstructural pattern of intestine embryogenesis. PMID:23754398

Ben Amar, Martine; Jia, Fei

2013-06-25

227

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

PubMed

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

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

2008-08-01

228

Plant regeneration from somatic embryos of Taxus brevifolia  

Microsoft Academic Search

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

Paula P. Chee

1996-01-01

229

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

230

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

PubMed Central

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

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

2013-01-01

231

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

SciTech Connect

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

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

2010-04-16

232

The Immunodominant Antigen of an Ultraviolet-induced Regressor Tumor Is Generated by a Somatic Point Mutation in the DEAD Box Helicase p68  

PubMed Central

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

Dubey, Purnima; Hendrickson, Ronald C.; Meredith, Stephen C.; Siegel, Christopher T.; Shabanowitz, Jeffrey; Skipper, Jonathan C.A.; Engelhard, Victor H.; Hunt, Donald F.; Schreiber, Hans

1997-01-01

233

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

PubMed Central

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

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

2003-01-01

234

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

235

Non-coding RNAs as regulators of embryogenesis  

PubMed Central

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

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

2014-01-01

236

Long-Term Vitamin-A-Deficiency Induces Alteration of Adult Mouse Spermatogenesis and Spermatogonial Differentiation: direct effect on spermatogonial gene expression and indirect effects via somatic cells  

PubMed Central

The objective of this study was to further understand the genetic mechanisms of Vitamin-A-Deficiency (VAD) induced arrest of spermatogonial stem-cell differentiation. Vitamin A and its derivatives (the retinoids) participate in many physiological processes including vision, cellular differentiation and reproduction. VAD affects spermatogenesis, the subject of our present study. Spermatogenesis is a highly regulated process of differentiation and complex morphologic alterations that leads to the formation of sperm in the seminiferous epithelium. VAD causes early cessation of spermatogenesis, characterized by degeneration of meiotic germ cells, leading to seminiferous tubules containing mostly type A spermatogonia and sertoli cells. These observations led us to the hypothesis that VAD affects not only germ cells but also somatic cells. To investigate the effects of VAD on spermatogenesis in mice we used adult Balb/C mice fed with Control or VAD diet for an extended period of time (6–28 weeks). We first observed the chronology, then the extent of the effects of VAD on the testes. Using microarray analysis of isolated pure populations of spermatogonia, leydig and sertoli cells from control and VAD 18- and 25-week mice, we examined the effects of VAD on gene expression and identified target genes involved in the arrest of spermatogonial differentiation and spermatogenesis. Our results provide a more precise definition of the chronology and magnitude of the consequences of VAD on mouse testes than the previously available literature, and highlight direct and indirect (via somatic cells) effects of VAD on germ cell differentiation. PMID:23253600

Boucheron-Houston, Catherine; Canterel-Thouennon, Lucile; Lee, Tin-Lap; Baxendale, Vanessa; Nagrani, Sohan; Chan, Wai-Yee; Rennert, Owen M.

2012-01-01

237

Silencing of Germline-Expressed Genes by DNA Elimination in Somatic Cells  

PubMed Central

SUMMARY Chromatin diminution is the programmed elimination of specific DNA sequences during development. It occurs in diverse species, but the function(s) of diminution and the specificity of sequence loss remain largely unknown. Diminution in the nematode Ascaris suum occurs during early embryonic cleavages and leads to the loss of germline genome sequences and the formation of a distinct genome in somatic cells. We found that ~43 Mb (~13%) of genome sequence is eliminated in A. suum somatic cells, including ~12.7 Mb of unique sequence. The eliminated sequences and location of the DNA breaks are the same in all somatic lineages from a single individual, and between different individuals. At least 685 genes are eliminated. These genes are preferentially expressed in the germline and during early embryogenesis. We propose that diminution is a mechanism of germline gene regulation that specifically removes a large number of genes involved in gametogenesis and early embryogenesis. PMID:23123092

Wang, Jianbin; Mitreva, Makedonka; Berriman, Matthew; Thorne, Alicia; Magrini, Vincent; Koutsovoulos, Georgios; Kumar, Sujai; Blaxter, Mark L.; Davis, Richard E.

2012-01-01

238

A carrot somatic embryo mutant is rescued by chitinase.  

PubMed Central

At the nonpermissive temperature, somatic embryogenesis of the temperature-sensitive (ts) carrot cell mutant ts11 does not proceed beyond the globular stage. This developmental arrest can be lifted by the addition of proteins secreted by wild-type cells to the culture medium. From this mixture of secreted proteins, a 32-kD glycoprotein, designated extracellular protein 3 (EP3), that allows completion of somatic embryo development in ts11 at the nonpermissive temperature was purified. On the basis of peptide sequences and biochemical characterization, EP3 was identified as a glycosylated acidic endochitinase. The addition of the 32-kD endochitinase to ts11 embryo cultures at the nonpermissive temperature appeared to promote the formation of a correctly formed embryo protoderm. These results imply that a glycosylated acidic endochitinase has an important function in early plant somatic embryo development. PMID:1498601

De Jong, A J; Cordewener, J; Lo Schiavo, F; Terzi, M; Vandekerckhove, J; Van Kammen, A; De Vries, S C

1992-01-01

239

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

240

[Embryogenesis of microspore derived multicells in Capsicum annuum L].  

PubMed

Microspores and derived multicells were isolated and cultured in modified liquid CP medium after a 15d's preculture of anthers on solidified medium. Thirty days later in suspension culture, at 28 degrees C dark condition embryoids with different developmental stages were formed. Up to 22 embryoids could be formed from the cell suspension of 12 anthers, and about 23% of the embryoids were at the cotyledonary stage. Fluorescence and light microscope observations revealed that these embryoids derived from microspores. After several symmetrical division of the nuclei of uninucleated microspores, multi-nuclei cells or multi-cells were formed, and developed further into embryoids. There were white hairs on the surface of pepper embryoids, and some embryoids showed low vigor while others showed normal by TTC staining. Plants could be formed from torpedo and cotyledonary stage embryoids on solidified medium. Embryoids could be induced by 7 degrees C, 32 degrees C or 35 degrees C stress treatment on anthers, Higher embryogenesis frequencies were got at 7 degrees C and 35 degrees C condition in anther culture while 35 degrees C and 32 degrees C treatment showed a higher embryogenesis in isolated multicell culture. The reason of this result was discussed. There were obvious differences in embryogenesis frequency among different genotypes and different temperature stress conditions. Flow cytometric analysis revealed that there were haploidy, doubled haploidy and haploid-diploid chimera in the regenerated plants. PMID:18198578

Liu, Fan; Zhao, Hong; Chen, Bin; Zhang, Yue Yun

2007-12-01

241

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

PubMed

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

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

2013-06-15

242

Rapid H1 linker histone transitions following fertilization or somatic cell nuclear transfer: evidence for a uniform developmental program in mice  

Microsoft Academic Search

H1 linker histones (H1s) are key regulators of chromatin structure and function. The functions of different H1s during early embryogenesis, and mechanisms regulating their associations with chromatin are largely unknown. The developmental transitions of H1s during oocyte growth and maturation, fertilization and early embryogenesis, and in cloned embryos were examined. Oocyte-specific H1FOO, but not somatic H1s, associated with chromatin in

Shaorong Gao; Young Gie Chung; Missag H Parseghian; Gretchen J King; Eli Y Adashi; Keith E Latham

2004-01-01

243

Somatic Expression of PyMT or Activated ErbB2 Induces Estrogen-Independent Mammary Tumorigenesis12  

PubMed Central

Estrogen signaling is required for the proliferation of normal breast epithelial cells. However, prophylactic inhibition of estrogen signaling fails to prevent 56% of human breast cancer cases. The underlying mechanism is not well understood. Aberrant activation of growth factor signaling is known to provide alternative proliferation pathways in breast cells that are fully transformed, but it is not known whether activation of growth factor signaling can substitute for estrogen signaling in causing aberrant proliferation in the normal breast epithelium. Here, we report that in a retrovirus-based somatic mouse model (replication-competent ALV-LTR splice acceptor/tumor virus A) that closely mimics the evolution of sporadic human breast cancers, mammary epithelial cells harboring PyMT or activated ErbB2 evolve into tumors independent of estrogen or other ovarian functions in contrast to previous observations of estrogen-dependent cancer formation in germ line mouse models of ErbB2 activation. Importantly, ErbB2 activation in normal mammary cells causes estrogen-independent proliferation in both estrogen receptor (ER)-negative cells as well as in normally quiescent ER-positive cells. Therefore, aberrant activation of growth factor signaling contributes to estrogen-independent proliferation of both preneoplastic and cancerous mammary cells, and prophylactic therapy against both growth factor signaling and estrogen signaling may need to be considered in women with increased risk of breast cancer. PMID:20824048

Toneff, Michael J; Du, Zhijun; Dong, Jie; Huang, Jian; Sinai, Parisa; Forman, James; Hilsenbeck, Susan; Schiff, Rachel; Huang, Shixia; Li, Yi

2010-01-01

244

Somatic expression of PyMT or activated ErbB2 induces estrogen-independent mammary tumorigenesis.  

PubMed

Estrogen signaling is required for the proliferation of normal breast epithelial cells. However, prophylactic inhibition of estrogen signaling fails to prevent 56% of human breast cancer cases. The underlying mechanism is not well understood. Aberrant activation of growth factor signaling is known to provide alternative proliferation pathways in breast cells that are fully transformed, but it is not known whether activation of growth factor signaling can substitute for estrogen signaling in causing aberrant proliferation in the normal breast epithelium. Here, we report that in a retrovirus-based somatic mouse model (replication-competent ALV-LTR splice acceptor/tumor virus A) that closely mimics the evolution of sporadic human breast cancers, mammary epithelial cells harboring PyMT or activated ErbB2 evolve into tumors independent of estrogen or other ovarian functions in contrast to previous observations of estrogen-dependent cancer formation in germ line mouse models of ErbB2 activation. Importantly, ErbB2 activation in normal mammary cells causes estrogen-independent proliferation in both estrogen receptor (ER)-negative cells as well as in normally quiescent ER-positive cells. Therefore, aberrant activation of growth factor signaling contributes to estrogen-independent proliferation of both preneoplastic and cancerous mammary cells, and prophylactic therapy against both growth factor signaling and estrogen signaling may need to be considered in women with increased risk of breast cancer. PMID:20824048

Toneff, Michael J; Du, Zhijun; Dong, Jie; Huang, Jian; Sinai, Parisa; Forman, James; Hilsenbeck, Susan; Schiff, Rachel; Huang, Shixia; Li, Yi

2010-09-01

245

Colchicine-induced microspore embryogenesis in coffee  

Microsoft Academic Search

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

J. C. Herrera; L. G. Moreno; J. R. Acuña; M. De Peña; D. Osorio

2002-01-01

246

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

PubMed Central

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

Sane, Djibril; Aberlenc-Bertossi, Frederique; Diatta, Leopold Ibrahima Djitiningo; Gueye, Badara; Daher, Abdourahman; Sagna, Maurice; Duval, Yves; Borgel, Alain

2012-01-01

247

Somatic cell genetics  

SciTech Connect

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

Davidson, R.L.

1984-01-01

248

Cognitive and somatic anxiety.  

PubMed

Three hundred and forty adults (including sports players, recreational exercisers, mediators and sedentary controls) completed three inventories purporting to measure cognitive and somatic aspects of anxiety. These were the Cognitive-Somatic Anxiety Questionnaire (CSAQ) devised by Schwartz, Davidson & Goleman (Psychosomatic Medicine, 40, 321-328, 1978), the Worry-Emotionality Scale (WES, Morris, Davis & Hutchens, Journal of Educational Psychology, 73, 541-555, 1981) and the Lehrer-Woolfolk (1982) Anxiety Symptom Questionnaire (LWASQ). Factor analysis of the CSAQ and WES identified distinct cognitive and somatic anxiety factors in both inventories. Higher somatic than cognitive ratings were recorded on the CSAQ and WES, while the pattern was reversed on the LWASQ. The CSAQ can tentatively be recommended as a useful measure of these two anxiety components. We were unable to confirm an observation made previously in the literature that practice of meditation is associated with reduced cognitive anxiety, or that exercise is linked with lower somatic anxiety. PMID:2405835

Steptoe, A; Kearsley, N

1990-01-01

249

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

SciTech Connect

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

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

1995-11-01

250

Significance of the zygotic seed coat on quiescence and desiccation tolerance of Medicago sativa L. somatic embryos  

Microsoft Academic Search

The influence of the zygotic seed coat on precocious germination and desiccation tolerance of somatic embryos has been studied using alfalfa (Medicago sativa L.). When cultured in contact with somatic embryos, seed coats at certain developmental stages inhibited precocious germination and induced desiccation tolerance in the somatic embryos. Germination of somatic embryos was inhibited by seed coats at the age

Tissa Senaratna; Praveen K. Saxena; Mulpuri V. Rao; John Afele

1995-01-01

251

Left-Right Asymmetry in Animal Embryogenesis  

E-print Network

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

Levin, Michael

252

Changes in DNA methylation levels and nuclear distribution patterns after microspore reprogramming to embryogenesis in barley.  

PubMed

Under specific stress treatments, the microspore can be induced in vitro to deviate from its gametophytic development and to reprogram towards embryogenesis, becoming a totipotent cell and forming haploid embryos. These can further regenerate homozygous plants for production of new isogenic lines, an important biotechnological tool for crop breeding. DNA methylation constitutes a prominent epigenetic modification of the chromatin fiber which regulates gene expression. Changes in DNA methylation accompany the reorganization of the nuclear architecture during plant cell differentiation and proliferation; however, the relationship between global DNA methylation and genome-wide expression patterns is still poorly understood. In this work, the dynamics of global DNA methylation levels and distribution patterns were analyzed during microspore reprogramming to embryogenesis and during pollen development in Hordeum vulgare. Quantification of global DNA methylation levels and 5-methyl-deoxycytidine (5mdC) immunofluorescence were conducted at specific stages of pollen development and after reprogramming to embryogenesis to analyze the epigenetic changes that accompany the change of developmental program and cell fate. The results showed low DNA methylation levels in microspores and a high increase along pollen development and maturation; an intense 5mdC signal was concentrated in the generative and sperm nuclei whereas the vegetative nucleus exhibited a weaker DNA methylation signal. After inductive stress treatment, low methylation levels and faint 5mdC signals were observed in nuclei of reprogrammed microspores and 2-4-cell proembryos. This data revealed a global DNA hypomethylation during the change of the developmental program and first embryogenic divisions. This is in contrast with the hypermethylation of generative and sperm cells of the male germline during pollen maturation, suggesting an epigenetic regulation after induction of microspore embryogenesis. At later embryogenesis stages, global DNA methylation progressively increased, accompanying embryo development and differentiation events like in zygotic embryos, corroborating that DNA methylation is critical for the regulation of gene expression in microspore embryogenesis. PMID:25074410

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

2014-01-01

253

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 precociously while XX germ cells fail to survive in an XY somatic environment. One of the major differences to assess whether meiosis is actively induced in the ovary, prevented in the pre-pubertal testis, or whether

Paris-Sud XI, Université de

254

The visceral and somatic antinociceptive effects of dihydrocodeine and its metabolite, dihydromorphine. A cross-over study with extensive and quinidine-induced poor metabolizers  

PubMed Central

Aims Dihydrocodeine is metabolized to dihydromorphine via the isoenzyme cytochrome P450 2D6, whose activity is determined by genetic polymorphism. The importance of the dihydromorphine metabolites for analgesia in poor metabolizers is unclear. The aim of this study was to assess the importance of the dihydromorphine metabolites of dihydrocodeine in analgesia by investigating the effects of dihydrocodeine on somatic and visceral pain thresholds in extensive and quinidine-induced poor metabolizers. Methods Eleven healthy subjects participated in a double-blind, randomized, placebo-controlled, four-way cross-over study comparing the effects of single doses of placebo and slow-release dihydrocodeine 60 mg with and without premedication with quinidine sulphate 50 mg on electrical, heat and rectal distension pain tolerance thresholds. Plasma concentrations and urinary excretion of dihydrocodeine and dihydromorphine were measured. Results In quinidine-induced poor metabolizers the plasma concentrations of dihydromorphine were reduced between 3 and 4 fold from 1.5 h to 13.5 h after dosing (P < 0.005) and urinary excretion of dihydromorphine in the first 12 h was decreased from 0.91% to 0.28% of the dihydrocodeine dose (P < 0.001). Dihydrocodeine significantly raised the heat pain tolerance thresholds (at 3.3 h and 5 h postdosing, P < 0.05) and the rectal distension defaecatory urge (at 3.3 h and 10 h postdosing, P < 0.02) and pain tolerance thresholds (at 3.3 h and 5 h postdosing, P < 0.05) compared with placebo. Premedication with quinidine did not change the effects of dihydrocodeine on pain thresholds, but decreased the effect of dihydrocodeine on defaecatory urge thresholds (at 1.5 h, 3.3 h and 10 h postdosing, P < 0.05). Conclusions In quinidine-induced poor metabolizers significant reduction in dihydromorphine metabolite production did not result in diminished analgesic effects of a single dose of dihydrocodeine. The metabolism of dihydrocodeine to dihydromorphine may therefore not be of clinical importance for analgesia. This conclusion must however, be confirmed with repeated dosing in patients with pain. PMID:9663813

Wilder-Smith, Clive H; Hufschmid, Edith; Thormann, Wolfgang

1998-01-01

255

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

PubMed Central

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

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

2011-01-01

256

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

PubMed

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

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

2014-11-01

257

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

258

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.

259

!l~ -g 'an 1 *It -!aiA Plant Embryogenesis  

E-print Network

formation (6, 7). Genetic manipulation of Arabidopsis thali- ana, by both chemical mutagenesis (8 information about the processes regulating higher plant embryogenesis. Both the genetic and mo- lecular

Goldberg, Robert B.

260

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

261

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

PubMed Central

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

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

2010-01-01

262

Embryogenesis and plant regeneration from tissue culture of Canada wildrye, Elymus canadensis L.  

PubMed

Somatic embryogenesis and plant regeneration of Canada wildrye (Elymus canadensis L.) from tissue culture was investigated by culturing immature embryos and inflorescences on MS medium containing 2 mg/l 2,4-D. The optimum size of explants for maximum embryogenic callus formation was 1.0 to 1.5 mm for embryos and 4 to 6 cm for inflorescences. Plant regeneration from the subcultured embryogenic callus was attempted monthly using hormone-free MS medium or MS medium with 0.5 mg/1 2,4-D and 0.3 mg/l GA3. Three hundred and fifty seven plantlets were regenerated from the callus cultures of both explant sources during a six month period. Ten chlorophyll deficient plants accounting for 2.8% of the total regenerants were observed. One plant with white striped leaves survived and was found to be an octoploid. PMID:24233228

Park, C H; Walton, P D

1989-05-01

263

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

264

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

265

Somatic cell nuclear transfer  

Microsoft Academic Search

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

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

2002-01-01

266

Changes in Gene Expression in Somatic Cells of Rat Testes Resulting from Hormonal Modulation and Radiation-Induced Germ Cell Depletion1  

PubMed Central

Although gonadotropins and androgen are required for normal spermatogenesis and both testosterone and follicle-stimulating hormone (FSH) are responsible for the inhibition of spermatogonial differentiation that occurs in irradiated rats, it has been difficult to identify the specific genes involved. To study specific hormonally regulated changes in somatic cell gene expression in the testis that may be involved in these processes, without the complication of changing populations of germ cells, we used irradiated LBNF1 rats, the testes of which contain almost exclusively somatic cells except for a few type A spermatogonia. Three different groups of these rats were treated with various combinations of gonadotropin-releasing hormone antagonist, an androgen receptor antagonist (flutamide), testosterone, and FSH, and we compared the gene expression levels 2 wk later to those of irradiated-only rats by microarray analysis. By dividing the gene expression patterns into three major patterns and 11 subpatterns, we successfully distinguished, in a single study, the genes that were specifically regulated by testosterone, by luteinizing hormone (LH), and by FSH from the large number of genes that were not hormonally regulated in the testis. We found that hormones produced more dramatic upregulation than downregulation of gene expression: Testosterone had the strongest upregulatory effect, LH had a modest but appreciable upregulatory effect, and FSH had a minor upregulatory effect. We also separately identified the somatic cell genes that were chronically upregulated by irradiation. Thus, the present study identified gene expression changes that may be responsible for hormonal action on somatic cells to support normal spermatogenesis and the hormone-mediated block in spermatogonial development after irradiation. PMID:19684331

Zhou, Wei; Bolden-Tiller, Olga U.; Shetty, Gunapala; Shao, Shan H.; Weng, Connie C.; Pakarinen, Pirjo; Liu, Zhilin; Stivers, David N.; Meistrich, Marvin L.

2009-01-01

267

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

Microsoft Academic Search

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

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

1994-01-01

268

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.

269

Real-time Embryogenesis in Live Caenorhabditis elegans Worms  

NSDL National Science Digital Library

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

Dr. Anita G Fernandez (Fairfield University Biology); Ian Chin-Sing (Queens University)

2011-11-21

270

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

271

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

272

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

273

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

Microsoft Academic Search

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

P. B. Kirti; V. L. Chopra

1990-01-01

274

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

Microsoft Academic Search

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

Hisato Kunitake; Masahiro Mii

1990-01-01

275

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

276

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

277

Somatic Mutagenesis in Autoimmunity  

PubMed Central

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

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

2013-01-01

278

Checkpoint kinase 1 negatively regulates somatic hypermutation  

PubMed Central

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

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

2014-01-01

279

Programmed Cell Death during Embryogenesis in Maize  

PubMed Central

Programmed cell death (PCD) in plants is considered an integral part of development. Evidence of DNA fragmentation, occurring at specific sites and times during embryo formation in maize (Zea mays L.), was obtained using terminal deoxyribonucleotidyl transferase?mediated dUTP?fluorescein nick end labelling (TUNEL) and by genomic DNA ladder detection. During the crucial period of elaboration of the primary shoot and root axis (14–20 d after pollination), TUNEL?positive nuclei are present in the scutellum, coleoptile, root cap and principally in the suspensor. Additional evidence of a form of programmed cell death occurring in these tissues comes from the detection of a DNA ladder. Upon completion of the differentiation process, all embryonic cells are TUNEL?negative, indicating that possible programmed cell death events during maize embryogenesis are confined to structures or organs that do not contribute to the adult plant body. PMID:12197527

GIULIANI, CONCETTA; CONSONNI, GABRIELLA; GAVAZZI, GIUSEPPE; COLOMBO, MONICA; DOLFINI, SILVANA

2002-01-01

280

High Genetic and Epigenetic Stability in Coffea arabica Plants Derived from Embryogenic Suspensions and Secondary Embryogenesis as Revealed by AFLP, MSAP and the Phenotypic Variation Rate  

PubMed Central

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

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

2013-01-01

281

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

282

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

PubMed Central

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

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

2008-01-01

283

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

PubMed Central

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

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

1996-01-01

284

Somatic disease and psychological disorder  

Microsoft Academic Search

The association between physical and psychological disorders has been demonstrated repeatedly. There are a number of explanations for this association, each of them pointing to specific diseases and operationalizations of mental distress. In this article, the relationship between various somatic diseases and a number of indices for psychological distress was investigated. Within one study population, patients with different somatic diseases

Peter F. M. Verhaak

1997-01-01

285

Increased intracranial pressure after diffuse traumatic brain injury exacerbates neuronal somatic membrane poration but not axonal injury: evidence for primary intracranial pressure-induced neuronal perturbation.  

PubMed

Increased intracranial pressure (ICP) associated with traumatic brain injury (TBI) is linked to increased morbidity. Although our understanding of the pathobiology of TBI has expanded, questions remain regarding the specific neuronal somatic and axonal damaging consequences of elevated ICP, independent of its impact on cerebral perfusion pressure (CPP). To investigate this, Fischer rats were subjected to moderate TBI. Measurements of ICP revealed two distinct responses to injury. One population exhibited transient increases in ICP that returned to baseline levels acutely, while the other displayed persistent ICP elevation (>20?mm?Hg). Utilizing these populations, the effect of elevated ICP on neuronal pathology associated with diffuse TBI was analyzed at 6?hours after TBI. No difference in axonal injury was observed, however, rats exhibiting persistently elevated ICP postinjury revealed a doubling of neurons with chronic membrane poration compared with rats exhibiting only transient increases in ICP. Elevated postinjury ICP was not associated with a concurrent increase in DNA damage; however, traditional histological assessments did reveal increased neuronal damage, potentially associated with redistribution of cathepsin-B from the lysosomal compartment into the cytosol. These findings indicate that persistently increased ICP, without deleterious alteration of CPP, exacerbates neuronal plasmalemmal perturbation that could precipitate persistent neuronal impairment and ultimate neuronal death. PMID:22781336

Lafrenaye, Audrey D; McGinn, Melissa J; Povlishock, John T

2012-10-01

286

Ophiobolin A from Bipolaris oryzae perturbs motility and membrane integrities of porcine sperm and induces cell death on mammalian somatic cell lines.  

PubMed

Bipolaris oryzae is a phytopathogenic fungus causing a brown spot disease in rice, and produces substance that strongly perturbs motility and membrane integrities of boar spermatozoa. The substance was isolated from the liquid culture of the fungal strain using extraction and a multi-step semi-preparative HPLC procedures. Based on the results of mass spectrometric and 2D NMR techniques, the bioactive molecule was identified as ophiobolin A, a previously described sesterterpene-type compound. The purified ophiobolin A exhibited strong motility inhibition and viability reduction on boar spermatozoa. Furthermore, it damaged the sperm mitochondria significantly at sublethal concentration by the dissipation of transmembrane potential in the mitochondrial inner membrane, while the plasma membrane permeability barrier remained intact. The study demonstrated that the cytotoxicity of ophiobolin A toward somatic cell lines is higher by 1-2 orders of magnitude compared to other mitochondriotoxic mycotoxins, and towards sperm cells unique by replacing the progressive motility by shivering tail beating at low exposure concentration. PMID:25251540

Bencsik, Ottó; Papp, Tamás; Berta, Máté; Zana, Annamária; Forgó, Péter; Dombi, György; Andersson, Maria A; Salkinoja-Salonen, Mirja; Vágvölgyi, Csaba; Szekeres, András

2014-09-01

287

Ophiobolin A from Bipolaris oryzae Perturbs Motility and Membrane Integrities of Porcine Sperm and Induces Cell Death on Mammalian Somatic Cell Lines  

PubMed Central

Bipolaris oryzae is a phytopathogenic fungus causing a brown spot disease in rice, and produces substance that strongly perturbs motility and membrane integrities of boar spermatozoa. The substance was isolated from the liquid culture of the fungal strain using extraction and a multi-step semi-preparative HPLC procedures. Based on the results of mass spectrometric and 2D NMR techniques, the bioactive molecule was identified as ophiobolin A, a previously described sesterterpene-type compound. The purified ophiobolin A exhibited strong motility inhibition and viability reduction on boar spermatozoa. Furthermore, it damaged the sperm mitochondria significantly at sublethal concentration by the dissipation of transmembrane potential in the mitochondrial inner membrane, while the plasma membrane permeability barrier remained intact. The study demonstrated that the cytotoxicity of ophiobolin A toward somatic cell lines is higher by 1–2 orders of magnitude compared to other mitochondriotoxic mycotoxins, and towards sperm cells unique by replacing the progressive motility by shivering tail beating at low exposure concentration. PMID:25251540

Bencsik, Otto; Papp, Tamas; Berta, Mate; Zana, Annamaria; Forgo, Peter; Dombi, Gyorgy; Andersson, Maria A.; Salkinoja-Salonen, Mirja; Vagvolgyi, Csaba; Szekeres, Andras

2014-01-01

288

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

289

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

290

Expression of periostin during Xenopus laevis embryogenesis.  

PubMed

Periostin (postn) is a secreted, extracellular matrix protein containing an EMI domain as well as four fasciclin I-like (Fas1) domains. Postn protein functions in cell adhesion, cell mobility, cell proliferation and gene regulation. Earlier studies have shown that postn is involved in different developmental processes such as somitogenesis, cardiogenesis and bone formation. Intriguingly, postn seems to be a very good candidate to establish novel therapies against cancer and chronic heart defects. Here we describe for the first time the spatio-temporal expression profile of postn during early development of Xenopus laevis. By semi-quantitative RT-PCR approaches, we demonstrate that postn is maternally expressed. Zygotic expression starts during early gastrulation and increases until stage 40. Whole mount in situ hybridization experiments revealed that postn is detectable in somites, the sensory layer of the epidermis, the roof plate, the notochord, the heart, migrating neural crest cells, cranial ganglia and forming cranial cartilage structures. Our results implicate a role of postn during Xenopus embryogenesis and represent a good starting point for future functional analyses. PMID:21901578

Tao, Si; Kühl, Michael; Kühl, Susanne J

2011-10-01

291

Mechanisms and models of somatic cell reprogramming.  

PubMed

Conversion of somatic cells to pluripotency by defined factors is a long and complex process that yields embryonic-stem-cell-like cells that vary in their developmental potential. To improve the quality of resulting induced pluripotent stem cells (iPSCs), which is important for potential therapeutic applications, and to address fundamental questions about control of cell identity, molecular mechanisms of the reprogramming process must be understood. Here we discuss recent discoveries regarding the role of reprogramming factors in remodelling the genome, including new insights into the function of MYC, and describe the different phases, markers and emerging models of reprogramming. PMID:23681063

Buganim, Yosef; Faddah, Dina A; Jaenisch, Rudolf

2013-06-01

292

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

293

Vitellin processing and protein synthesis during cricket embryogenesis.  

PubMed

At the start of insect embryogenesis most of the protein mass of the egg cytoplasm exists as vitellin (Vt) obtained endocytically during vitellogenesis. Of the new embryo polypeptides (EP) appearing in the egg during embryogenesis, many are synthesized de novo, while, in some species, others derive from developmentally programmed partial proteolysis of Vt. Earlier we showed that by the end of vitellogenesis the two native Vts in Acheta domesticus exist in opposing gradients along the longitudinal axis of the egg. Here we hypothesize that this ooplasmic Vt distribution presents a milieu for Vt processing out of which region-specific regulatory molecules could arise. The metabolic origin and stage-specific patterns of seven predominant EPs (EP 1-7) identified by SDS-PAGE were examined and the results correlated with developmental morphology during the 14 days of embryogenesis. Based on antibody reactivity, peptide mapping and in vitro radiolabeling, we determined that EPs 1-3, 6 and 7 are Vt-derived, while EPs 4 and 5 are produced de novo by the embryo. The five Vt-derived EPs appear during the first 24 h of embryogenesis when migrating cleavage nuclei and associated cytoplasm form the cellular blastoderm, and levels of EPs 4 and 5 increase during days 4-6 of embryogenesis when katatrepsis and yolk mass contraction occur. Positive periodic acid-Schiff staining indicated that EPs 1-3 and their Vt-precursor polypeptides are glycoproteins. This work shows that developmental stage-specific Vt processing occurs during A. domesticus embryogenesis and points next to investigation of the functional significance of Vt cleavage products during development. PMID:9818388

Handley, H L; Estridge, B H; Bradley, J T

1998-11-01

294

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

PubMed

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

Soriano, Mercedes; Li, Hui; Boutilier, Kim

2013-09-01

295

[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

296

A Novel Mouse Model for the Hyper-IgM Syndrome: A Spontaneous Activation-Induced Cytidine Deaminase Mutation Leading to Complete Loss of Ig Class Switching and Reduced Somatic Hypermutation.  

PubMed

We describe a spontaneously derived mouse line that completely failed to induce Ig class switching in vitro and in vivo. The mice inherited abolished IgG serum titers in a recessive manner caused by a spontaneous G?A transition mutation in codon 112 of the aicda gene, leading to an arginine to histidine replacement (AID(R112H)). Ig class switching was completely reconstituted by expressing wild-type AID. Mice homozygous for AID(R112H) had peripheral B cell hyperplasia and large germinal centers in the absence of Ag challenge. Immunization with SRBCs elicited an Ag-specific IgG1 response in wild-type mice, whereas AID(R112H) mice failed to produce IgG1 and had reduced somatic hypermutation. The phenotype recapitulates the human hyper-IgM (HIGM) syndrome that is caused by point mutations in the orthologous gene in humans, and the AID(R112H) mutation is frequently found in HIGM patients. The AID(R112H) mouse model for HIGM provides a powerful and more precise tool than conventional knockout strategies. PMID:25252954

Dahlberg, Carin I M; He, Minghui; Visnes, Torkild; Torres, Magda Liz; Cortizas, Elena M; Verdun, Ramiro E; Westerberg, Lisa S; Severinson, Eva; Ström, Lena

2014-11-01

297

A Novel Mouse Model for the Hyper-IgM Syndrome: A Spontaneous Activation-Induced Cytidine Deaminase Mutation Leading to Complete Loss of Ig Class Switching and Reduced Somatic Hypermutation  

PubMed Central

We describe a spontaneously derived mouse line that completely failed to induce Ig class switching in vitro and in vivo. The mice inherited abolished IgG serum titers in a recessive manner caused by a spontaneous G?A transition mutation in codon 112 of the aicda gene, leading to an arginine to histidine replacement (AIDR112H). Ig class switching was completely reconstituted by expressing wild-type AID. Mice homozygous for AIDR112H had peripheral B cell hyperplasia and large germinal centers in the absence of Ag challenge. Immunization with SRBCs elicited an Ag-specific IgG1 response in wild-type mice, whereas AIDR112H mice failed to produce IgG1 and had reduced somatic hypermutation. The phenotype recapitulates the human hyper-IgM (HIGM) syndrome that is caused by point mutations in the orthologous gene in humans, and the AIDR112H mutation is frequently found in HIGM patients. The AIDR112H mouse model for HIGM provides a powerful and more precise tool than conventional knockout strategies. PMID:25252954

Dahlberg, Carin I. M.; He, Minghui; Visnes, Torkild; Torres, Magda Liz; Cortizas, Elena M.; Verdun, Ramiro E.; Strom, Lena

2014-01-01

298

INTRODUCTION During embryogenesis, neurons of the cerebral cortex are  

E-print Network

INTRODUCTION During embryogenesis, neurons of the cerebral cortex are generated in the ventricular in the cerebral cortex employed glia as their sole substratum and consequently followed strictly radial pathways., 1988; Turner and Cepko, 1987; Wetts and Fraser, 1988), clones in the cerebral cortex spread

McConnell, Susan

299

Cyclin E2 is required for embryogenesis in Xenopus laevis  

Microsoft Academic Search

In mammalian cells, E-type cyclins (E1 and E2) are generally believed to be required for entry into S phase. However, in mice, cyclin E is largely dispensable for normal embryogenesis. Moreover, Drosophila cyclin E plays a critical role in cell fate determination in neural lineages independently of proliferation. Thus, the functions of cyclin E, particularly during early development, remain elusive.

Tetsuya Gotoh; Noriko Shigemoto; Takeo Kishimoto

2007-01-01

300

Plant regeneration of Korean wild ginseng (Panax ginseng Meyer) mutant lines induced by ?-irradiation ((60)Co) of adventitious roots.  

PubMed

An efficient in vitro protocol has been established for somatic embryogenesis and plantlet conversion of Korean wild ginseng (Panax ginseng Meyer). Wild-type and mutant adventitious roots derived from the ginseng produced calluses on Murashige and Skoog (MS) medium supplemented with 0.5 mg/L 2,4-dichlorophenoxyacetic acid and 0.3 mg/L kinetin; 53.3% of the explants formed callus. Embryogenic callus proliferation and somatic embryo induction occurred on MS medium containing 0.5 mg/L 2,4-dichlorophenoxyacetic acid. The induced somatic embryos further developed to maturity on MS medium with 5 mg/L gibberellic acid, and 85% of them germinated. The germinated embryos were developed to shoots and elongated on MS medium with 5 mg/L gibberellic acid. The shoots developed into plants with well-developed taproots on one-third strength Schenk and Hildebrandt basal medium supplemented with 0.25 mg/L 1-naphthaleneacetic acid. When the plants were transferred to soil, about 30% of the regenerated plants developed into normal plants. PMID:25378998

Zhang, Jun-Ying; Sun, Hyeon-Jin; Song, In-Ja; Bae, Tae-Woong; Kang, Hong-Gyu; Ko, Suk-Min; Kwon, Yong-Ik; Kim, Il-Woung; Lee, Jaechun; Park, Shin-Young; Lim, Pyung-Ok; Kim, Yong Hwan; Lee, Hyo-Yeon

2014-07-01

301

P DNA element movement in somatic cells reduces lifespan in Drosophila melanogaster: evidence in support of the somatic mutation theory of aging  

Microsoft Academic Search

Evidence is presented in support of the hypothesis that P DNA element movement in somatic cells of Drosophila melanogaster induces genetic damage that significantly reduces lifespan. The lifespan of D. melanogaster males was significantly reduced by the somatic movement of a single P element in the presence of P[ry+ ?2–3](99B) transposase. In addition, the P[ry+ SalI](89D) repressor of P[ry+ ?2–3](99B)

R. C. Woodruff; A. G. Nikitin

1995-01-01

302

Somatic variation in Lolium perenne  

Microsoft Academic Search

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

Y Shimamoto; M D Hayward

1975-01-01

303

Testicular Somatic Cells, not Gonocytes, Are the Major Source of Functional Activin A during Testis Morphogenesis  

PubMed Central

Proper development of the seminiferous tubules (or testis cords in embryos) is critical for male fertility. Sertoli cells, somatic components of the seminiferous tubules, serve as nurse cells to the male germline, and thus their numbers decide the quantity of sperm output in adulthood. We previously identified activin A, the protein product of the activin ?A (Inhba) gene, as a key regulator of murine Sertoli cell proliferation and testis cord expansion during embryogenesis. Although our genetic studies implicated fetal Leydig cells as the primary producers of testicular activin A, gonocytes are another potential source. To investigate the relative contribution of gonocyte-derived activin A to testis morphogenesis, we compared testis development in the Inhba global knockout mouse, which lacks activin A production in all cells (including the gonocytes), and a steroidogenic factor 1 (Sf1)-specific conditional knockout model in which activin A expression in testicular somatic cells is disrupted but gonocyte expression of activin A remains intact. Surprisingly, testis development was comparable in these two models of activin A insufficiency, with similar reductions in Sertoli cell proliferation and minor differences in testis histology. Thus, our findings suggest activin A from male gonocytes is insufficient to promote Sertoli cell proliferation and testis cord expansion in the absence of somatic cell-derived activin A. Evaluation of adult male mice with fetal disruption of activin A revealed reduced testis size, lowered sperm production, altered testicular histology, and elevated plasma FSH levels, defects reminiscent of human cases of androgen-sufficient idiopathic oligozoospermia. PMID:21952240

Archambeault, Denise R.; Tomaszewski, Jessica; Childs, Andrew J.; Anderson, Richard A.

2011-01-01

304

Cryopreservation of zygotic embryonic axes and somatic embryos of European chestnut.  

PubMed

For Castanea sativa (European chestnut), a species with recalcitrant seeds that is not easily propagated vegetatively, cryopreservation is one of the most promising techniques for maintaining genetic resource diversity and for conservation of selected germplasms. Long-term conservation of selected seeds and valuable embryogenic lines can be achieved through the cryopreservation of zygotic embryonic axes and somatic embryos, respectively. This chapter describes methods for the desiccation-based cryostorage of zygotic embryonic axes, and the vitrification-based cryopreservation of somatic embryos. For zygotic embryonic axes, the highest post-thaw survival and plantlet recovery rates are obtained by desiccation in a laminar flow hood to 20-25% moisture content, followed by direct immersion in liquid nitrogen. For somatic embryos, embryogenesis resumption rates of over 60% are achieved by preculture of embryo clumps for 3 days on solid medium containing 0.3 M sucrose, incubation in PVS2 vitrification solution for 60 min at 0°C, and direct immersion in liquid nitrogen. Plantlet recovery from cryostored embryogenic lines requires proliferation of the thawed embryos and subsequent maturation before germination and conversion into plantlets. PMID:21207271

Vieitez, Ana M; San-José, M Carmen; Corredoira, Elena

2011-01-01

305

Vasodilatation of muscle microvessels induced by somatic afferent stimulation is mediated by calcitonin gene-related peptide release in the rat.  

PubMed

In anesthesized rats, the effects of electrical stimulation (ES) to the saphenous nerve on the microcirculation of the gracilis muscle were assessed through the measurement of two different hemodynamic parameters: (a). the muscle blood flow (MBF) using a laser Doppler flowmeter; and (b). the changes in diameter of the muscle arterioles observed directly using an intravital microscope system. Ipsilateral ES (5 V, 20 Hz, for 30 s) produced increases in MBF and mean arterial pressure (47+/-10% and 18+/-5%) over the baseline, while no significant changes in MBF were observed in the contralateral muscle. Neither selective nor simultaneous alpha- and beta-adrenergic blockade altered the increases in MBF induced by ipsilateral ES. The arteriolar diameter was found to increase by 38.9+/-5% following ipsilateral ES. This response in diameter was abolished after the topical application of a calcitonin gene-related peptide receptor antagonist (CGRP(8-37)). Contralateral ES produced a decrease in arteriolar diameter by 26+/-14%. Thus, ipsilateral nerve ES produced vasodilative responses in the muscle accompanied by increases in MBF independently of the sympathetic activity. Furthermore, CGRP was found directly involved in the reflex neural regulation of the muscle microcirculation, which suggests the participation of an axon reflex mechanism. PMID:12419499

Loaiza, Lázaro A; Yamaguchi, Shinjiro; Ito, Momoyo; Ohshima, Norio

2002-11-22

306

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

307

Bisphenol A induces otolith malformations during vertebrate embryogenesis  

Microsoft Academic Search

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

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

2011-01-01

308

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

309

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

310

Genome-wide analysis reveals divergent patterns of gene expression during zygotic and somatic embryo maturation of Theobroma cacao L., the chocolate tree  

PubMed Central

Background Theobroma cacao L. is a tropical fruit tree, the seeds of which are used to create chocolate. In vitro somatic embryogenesis (SE) of cacao is a propagation system useful for rapid mass-multiplication to accelerate breeding programs and to provide plants directly to farmers. Two major limitations of cacao SE remain: the efficiency of embryo production is highly genotype dependent and the lack of full cotyledon development results in low embryo to plant conversion rates. With the goal to better understand SE development and to improve the efficiency of SE conversion we examined gene expression differences between zygotic and somatic embryos using a whole genome microarray. Results The expression of 28,752 genes was determined at 4 developmental time points during zygotic embryogenesis (ZE) and 2 time points during cacao somatic embryogenesis (SE). Within the ZE time course, 10,288 differentially expressed genes were enriched for functions related to responses to abiotic and biotic stimulus, metabolic and cellular processes. A comparison ZE and SE expression profiles identified 10,175 differentially expressed genes. Many TF genes, putatively involved in ethylene metabolism and response, were more strongly expressed in SEs as compared to ZEs. Expression levels of genes involved in fatty acid metabolism, flavonoid biosynthesis and seed storage protein genes were also differentially expressed in the two types of embryos. Conclusions Large numbers of genes were differentially regulated during various stages of both ZE and SE development in cacao. The relatively higher expression of ethylene and flavonoid related genes during SE suggests that the developing tissues may be experiencing high levels of stress during SE maturation caused by the in vitro environment. The expression of genes involved in the synthesis of auxin, polyunsaturated fatty acids and secondary metabolites was higher in SEs relative to ZEs despite lack of lipid and metabolite accumulation. These differences in gene transcript levels associated with critical processes during seed development are consistent with the fact that somatic embryos do not fully develop the large storage cotyledons found in zygotic embryos. These results provide insight towards design of improved protocols for cacao somatic embryogenesis. PMID:25030026

2014-01-01

311

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

312

Custos controls ?-catenin to regulate head development during vertebrate embryogenesis.  

PubMed

Precise control of the canonical Wnt pathway is crucial in embryogenesis and all stages of life, and dysregulation of this pathway is implicated in many human diseases including cancers and birth defect disorders. A key aspect of canonical Wnt signaling is the cytoplasmic to nuclear translocation of ?-catenin, a process that remains incompletely understood. Here we report the identification of a previously undescribed component of the canonical Wnt signaling pathway termed Custos, originally isolated as a Dishevelled-interacting protein. Custos contains casein kinase phosphorylation sites and nuclear localization sequences. In Xenopus, custos mRNA is expressed maternally and then widely throughout embryogenesis. Depletion or overexpression of Custos produced defective anterior head structures by inhibiting the formation of the Spemann-Mangold organizer. In addition, Custos expression blocked secondary axis induction by positive signaling components of the canonical Wnt pathway and inhibited ?-catenin/TCF-dependent transcription. Custos binds to ?-catenin in a Wnt responsive manner without affecting its stability, but rather modulates the cytoplasmic to nuclear translocation of ?-catenin. This effect on nuclear import appears to be the mechanism by which Custos inhibits canonical Wnt signaling. The function of Custos is conserved as loss-of-function and gain-of-function studies in zebrafish also demonstrate a role for Custos in anterior head development. Our studies suggest a role for Custos in fine-tuning canonical Wnt signal transduction during embryogenesis, adding an additional layer of regulatory control in the Wnt-?-catenin signal transduction cascade. PMID:25157132

Komiya, Yuko; Mandrekar, Noopur; Sato, Akira; Dawid, Igor B; Habas, Raymond

2014-09-01

313

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

314

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

315

Somatic disease and psychological disorder.  

PubMed

The association between physical and psychological disorders has been demonstrated repeatedly. There are a number of explanations for this association, each of them pointing to specific diseases and operationalizations of mental distress. In this article, the relationship between various somatic diseases and a number of indices for psychological distress was investigated. Within one study population, patients with different somatic diseases were identified, and their experience with mental distress, their requests for help from their GP during consultations, and their GPs' diagnoses were registered and compared with the total study population: It appears that relationships could be demonstrated between experience of distress and presentation of psychological symptoms during consultations, on the one hand, and common physical disorders, on the other. Patients with neurological diseases (Parkinson's, epilepsy, multiple sclerosis) and gastric ulcers showed the same relationships, but were also more frequently diagnosed by the GP as having psychological disorders. Patients with a number of other serious somatic diseases, such as diabetes, cancer, and arthritis, did not distinguish themselves in a positive way on one of indices for psychological distress. PMID:9130183

Verhaak, P F

1997-03-01

316

Transformation of white spruce ( Picea glauca) somatic embryos by microprojectile bombardment  

Microsoft Academic Search

Cotyledonary somatic embryos of white spruce [Picea glauca (Moench) Voss] were subjected to microprojectile bombardment with a gene construct containing a gus::nptll fusion gene. Somatic embryos were used to re-induce the embryogenic tissue after bombardments. Histochemical assay using X-gluc as a substrate showed that all the embryos (100%) were GUS positive 48 h after bombardment. However, only thirteen out of

V. R. Bommineni; R. N. Chibbar; R. S. S. Datla; E. W. T. Tsang

1993-01-01

317

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

318

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

319

Somatic embryogenesis in loblolly pine ( Pinus taeda L.): improving culture initiation with abscisic acid and silver nitrate  

Microsoft Academic Search

Loblolly pine ( Pinus taeda L.) culture initiation was improved by the addition of abscisic acid (ABA) (3.7 µ M), silver nitrate (20  µ M), and guanosine 3',5'-cyclic monophosphate, 8-bromo-, sodium salt (10 µ M) to the medium and by raising cytokinin levels in the presence of 50 mg\\/l activated carbon (AC). Basal medium contained modified 1\\/2-P6 salts, 50 mg\\/l AC, Cu and Zn added

G. S. Pullman; K. Namjoshi; Y. Zhang

2003-01-01

320

The role of Somatic embryogenesis receptor-like kinase 1 in controlling pollen production of the Gossypium anther.  

PubMed

In flowering plants, male gametophytes are generated in anthers from microsporocytes. However, more evidence is needed to reveal the genetic mechanisms which regulate the differentiation and interaction of these highly specialized cells in anthers. Here we report the characterization of a series of male-sterile cotton (Gossypium hirsutum) mutants, including mutants with normal fertility, semi-sterility and complete sterility. These mutants are forms of transgenic cotton containing RNAi vectors with partial cDNA fragments of GhSERK1. The GhSERK1 gene encodes a putative leucine-rich repeat receptor protein kinase (LRR-RLK), and generally has 11 domains. In previous research, we found plants containing GhSERK1 produce an abundance of male reproductive tissue. In this paper, three RNAi constructs were designed separately to analyze its function in anther. After the three RNAi vectors were transformed into the cotton, transgenic plants with the specialized fragment exhibited normal fertility or the pollen energy decreased slightly, as ones with the homologous fragments exhibited various degrees of male sterility with different expression levels of GhSERK1 mRNA. In conclusion, for the transgenic plants with conserved fragments, lower expression levels of GhSERK1 mRNA were in transgenic plants, and a higher degree of male sterility was observed. Taking together, these findings demonstrate the GhSERK1 gene has a role in the development of anthers, especially in the formation of pollen grains. Also, we infer there must be another homolog of GhSERK1 in cotton, and both of GhSERK1 and its homolog function redundantly as important control points in controlling anther pollen production. PMID:24276918

Shi, Ya-li; Guo, San-dui; Zhang, Rui; Meng, Zhi-gang; Ren, Mao-zhi

2014-01-01

321

Genotype and auxin influence direct somatic embryogenesis from protoplasts derived from embryogenic cell suspensions of Asparagus officinalis L  

Microsoft Academic Search

Embryogenic callus from four asparagus genotypes, Jersey Giant No. 8, MD10, Rutgers 22, and 86SOM1 was simultaneously initiated from spear explants on semisolid LS medium containing 5 ?M 2,4-D or 50 ?M NAA. Calluses were used to initiate cell suspensions in liquid LS medium of the same composition. The eight sets of cell suspensions were used as protoplast donors at

Roger A. May; Kenneth C. Sink

1995-01-01

322

Amygdala activation by corticosterone alters visceral and somatic pain in cycling female rats.  

PubMed

Irritable bowel syndrome (IBS) is often seen in women, and symptom severity is known to vary over the menstrual cycle. In addition, activation of the hypothalamic-pituitary-adrenal (HPA) axis enhances symptomology and patients with IBS have increased activation of the amygdala, a brain region known to facilitate HPA output. However, little is known about the effects of amygdala activation during different stages of the menstrual cycle. We therefore investigated the effects of amygdala activation on somatic and visceral pain perception over the rat estrous cycle. Female Wistar rats were implanted with either corticosterone (Cort) or cholesterol as a control onto the dorsal margin of the central amygdala. Visceral sensitivity was quantified by recording the visceromotor response (VMR) to colorectal distension (CRD) and somatic sensitivity was assessed via the Von Frey test. In cholesterol controls, both visceral and somatic sensitivity varied over the estrous cycle. Rats in proestrus/estrus responded to CRD with an increased VMR compared with rats in metestrus/diestrus. Somatic sensitivity followed a similar pattern with enhanced sensitivity during proestrus/estrus compared with metestrus/diestrus. Elevated amygdala Cort induced visceral hypersensitivity during metestrus/diestrus but had no effect during proestrus/estrus. In contrast, elevated amygdala Cort increased somatic sensitivity during both metestrus/diestrus and proestrus/estrous. These results suggests that amygdala activation by Cort eliminates spontaneously occurring differences in visceral and somatic pain perception, which could explain the lowered pain thresholds and higher incidence of somatic pain observed in women with IBS. PMID:21454447

Gustafsson, Jenny K; Greenwood-Van Meerveld, Beverley

2011-06-01

323

In vivo imaging of zebrafish embryogenesis.  

PubMed

The zebrafish Danio rerio has emerged as a powerful vertebrate model system that lends itself particularly well to quantitative investigations with live imaging approaches, owing to its exceptionally high optical clarity in embryonic and larval stages. Recent advances in light microscopy technology enable comprehensive analyses of cellular dynamics during zebrafish embryonic development, systematic mapping of gene expression dynamics, quantitative reconstruction of mutant phenotypes and the system-level biophysical study of morphogenesis. Despite these technical breakthroughs, it remains challenging to design and implement experiments for in vivo long-term imaging at high spatio-temporal resolution. This article discusses the fundamental challenges in zebrafish long-term live imaging, provides experimental protocols and highlights key properties and capabilities of advanced fluorescence microscopes. The article focuses in particular on experimental assays based on light sheet-based fluorescence microscopy, an emerging imaging technology that achieves exceptionally high imaging speeds and excellent signal-to-noise ratios, while minimizing light-induced damage to the specimen. This unique combination of capabilities makes light sheet microscopy an indispensable tool for the in vivo long-term imaging of large developing organisms. PMID:23523701

Keller, Philipp J

2013-08-15

324

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

325

Neurenteric cysts of the posterior fossa: recognition, management, and embryogenesis.  

PubMed

Neurenteric cysts are endothelium-lined structures most commonly encountered in the lower cervical or upper thoracic spinal cord. The occurrence of neurenteric cysts within the cranial vault is unusual. We present three patients with neurenteric cysts located within the posterior fossa: one near the jugular foramen deforming the 4th ventricle, a second in the cerebellopontine angle, and a third in the prepontine cistern. Several different theories have been advanced to explain the embryogenesis of neurenteric cysts. We review these theories and conclude that cranial neurenteric cysts may arise from a disturbance of early gastrulation, shortly after the onset of primitive streak regression. PMID:1758603

Harris, C P; Dias, M S; Brockmeyer, D L; Townsend, J J; Willis, B K; Apfelbaum, R I

1991-12-01

326

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

PubMed Central

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

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

2014-01-01

327

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

328

[Therapeutic cloning and somatic cell reprogramming: every road leads to Rome].  

PubMed

The researches of therapeutic cloning and somatic cell reprogramming, two strategies used to generate patient-specific autologous stem cells, have recently made great progress. Therapeutic cloning refers to derivation of embryonic stem cells from blastocyst produced by somatic cell nuclear transfer, whereas somatic cell reprogramming refers to establishment of induced pluripotent stem (iPS) cells from differentiated somatic cells by ectopic expression of specific transcription factors. The two strategies differ in their methodological approaches, technical obstacles and ethical debates, but confront similar problems including the differentiation of stem cells and the feasibility of cell-replacement therapy. This review discusses the research advance of these two biotechnologies and summarizes their difference and similarity. PMID:19558136

Yang, Jin; Liu, Guo-Qiang; Hong, Tian-Pei

2009-04-01

329

Somatic neurosis in Muslim women in India  

Microsoft Academic Search

A chronic neurotic syndrome among Muslim women in India with predominantly somatic multiple symptomatology is briefly described. It is suggested that the syndrome is distinctive in its clinical features and in the cultural background of the patients. Pending resolution of its nosological status it is referred to as Somatic neurosis. In an attempt to determine its nature a group of

N. Janakiramaiah; D. K. Subbakrishna

1980-01-01

330

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

331

SOMATIC EMBRYOS OF CLONAL BURBANK PARADOX WALNUT  

Microsoft Academic Search

Somatic embryos are used in our procedure for inserting new genes into walnuts. Historically, we have used somatic embryo cultures derived from zygotic tissue, specifically the immature cotyledon. In 1995 we obtained embryo cultures from maternal anther tissue of 'Chandler' walnut but were unable to duplicate the results with other cultivars. This year the sterile anthers of paradox 'Burbank' were

Mary Lou Mendum; Soussan Hirbod; Chuck Leslie; Gale McGranahan

332

Integrative analysis of a cancer somatic mutome  

Microsoft Academic Search

BACKGROUND: The consecutive acquisition of genetic alterations characterizes neoplastic processes. As a consequence of these alterations, molecular interactions are reprogrammed in the context of highly connected and regulated cellular networks. The recent identification of the collection of somatically mutated genes in breast tumors (breast cancer somatic \\

Pilar Hernández; Xavier Solé; Joan Valls; Víctor Moreno; Gabriel Capellá; Ander Urruticoechea; Miguel Angel Pujana

2007-01-01

333

Somatic Cell Nuclear Transfer in the Mouse  

Microsoft Academic Search

Somatic cell nuclear transfer (SCNT) has become a unique and powerful tool for epigenetic reprogramming research and gene manipulation in animals since ``Dolly,'' the first animal cloned from an adult cell was reported in 1997. Although the success rates of somatic cloning have been inefficient and the mechanism of reprogramming is still largely unknown, this technique has been proven to

Satoshi Kishigami; Teruhiko Wakayama

2009-01-01

334

G-protein-coupled estrogen receptor 1 is involved in brain development during zebrafish (Danio rerio) embryogenesis  

SciTech Connect

Highlights: •The Gper expression was detected in the developing brain of zebrafish. •Gper morpholino knockdown induced apoptosis of brain cells. •Gper morpholino knockdown reduced expression in neuron markers. •Zebrafish Gper may be involved in neuronal development. -- Abstract: G-protein-coupled estrogen receptor 1 (Gper, formerly known as GPR30) is found to be a trophic and protective factor in mediating action of estrogen in adult brain, while its role in developing brain remains to be elucidated. Here we present the expression pattern of Gper and its functions during embryogenesis in zebrafish. Both the mRNA and protein of Gper were detected throughout embryogenesis. Whole mount in situ hybridization (WISH) revealed a wide distribution of gper mRNAs in various regions of the developing brain. Gper knockdown by specific morpholinos resulted in growth retardation in embryos and morphological defects in the developing brain. In addition, induced apoptosis, decreased proliferation of the brain cells and maldevelopment of sensory and motor neurons were also found in the morphants. Our results provide novel insights into Gper functions in the developing brain, revealing that Gper can maintain the survival of the brain cells, and formation and/or differentiation of the sensory and motor neurons.

Shi, Yanan; Liu, Xiaochun [State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275 (China)] [State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275 (China); Zhu, Pei; Li, Jianzhen; Sham, Kathy W.Y. [School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China)] [School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China); Cheng, Shuk Han [Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (China)] [Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong (China); Li, Shuisheng; Zhang, Yong [State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275 (China)] [State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275 (China); Cheng, Christopher H.K., E-mail: chkcheng@cuhk.edu.hk [School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China); Lin, Haoran, E-mail: lsslhr@mail.sysu.edu.cn [State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275 (China) [State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275 (China); College of Ocean, Hainan University, Haikou 570228, Hainan (China)

2013-05-24

335

Reporter genes for embryogenesis research in livestock species.  

PubMed

Currently, our knowledge of early mammalian embryogenesis, stem cell differentiation and development is largely based on studies performed in mouse models. However, in important aspects, e.g. the timing of epigenetic reprogramming and embryonic genome activation, livestock species probably reflect far more closely the situation in men and other non-rodent mammals. A major challenge is the fact that in mammals, the development of individual zygotes is highly variable and vulnerable, and the outcome is uncertain. Valid indicators of the highly heterogeneous development and health status, and the actual developmental potential of individual oocytes, zygotes or embryos would be crucially important to tap the full power of holistic transcriptome and proteome analyses. Fluorescent reporter proteins opened new vistas for embryology and stem cell research: they can be used as reporters for the activity of gene promoters or tagged to functional proteins to study their intracellular localization in living cells, tissues and organisms. Fluorescent reporter genes may be used to microscopically observe key processes of early development. Thus, novel information related to developmental potential can be obtained from living embryos before processing them, e.g. for "-omic" studies. This review summarizes the main current reporter gene techniques and gene transfer approaches, which might be suitable for the investigation of early embryogenesis in livestock mammals. The potential of promoter reporter genes is exemplified by a bovine model system for quantitative monitoring of transcriptional reactivation of the so-called pluripotency gene POU5F1 in cloned bovine embryos. PMID:17583783

Habermann, F A; Wuensch, A; Sinowatz, F; Wolf, E

2007-09-01

336

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

337

Somatic Symptoms Evoked by Exam Stress in University Students: The Role of Alexithymia, Neuroticism, Anxiety and Depression  

PubMed Central

Objective The etiology of somatization is incompletely understood, but could be elucidated by models of psychosocial stress. Academic exam stress has effectively been applied as a naturalistic stress model, however its effect on somatization symptoms according to ICD-10 and DSM-IV criteria has not been reported so far. Baseline associations between somatization and personality traits, such as alexithymia, have been studied exhaustively. Nevertheless, it is largely unknown if personality traits have an explanatory value for stress induced somatization. Methods This longitudinal, quasi-experimental study assessed the effects of university exams on somatization — and the reversal of effects after an exam-free period. Repeated-observations were obtained within 150 students, measuring symptom intensity before, during and after an exam period, according to the Screening for Somatoform Symptoms 7-day (SOMS-7d). Additionally, self-reports on health status were used to differentiate between medically explained and medically unexplained symptoms. Alexithymia, neuroticism, trait-anxiety and baseline depression were surveyed using the Toronto-Alexithymia Scale (TAS-20), the Big-Five Personality Interview (NEO-FFI), the State Trait Anxiety Inventory (STAI) and Beck’s Depression Inventory (BDI-II). These traits were competitively tested for their ability to explain somatization increases under exam stress. Results Somatization significantly increased across a wide range of symptoms under exam stress, while health reports pointed towards a reduction in acute infections and injuries. Neuroticism, alexithymia, trait anxiety and depression explained variance in somatization at baseline, but only neuroticism was associated with symptom increases under exam stress. Conclusion Exam stress is an effective psychosocial stress model inducing somatization. A comprehensive quantitative description of bodily symptoms under exam stress is supplied. The results do not support the stress-alexithymia hypothesis, but favor neuroticism as a personality trait of importance for somatization. PMID:24367700

Zunhammer, Matthias; Eberle, Hanna; Eichhammer, Peter; Busch, Volker

2013-01-01

338

DNA recombination in somatic plant cells: mechanisms and evolutionary consequences.  

PubMed

In somatic cells, recombination is a means of DNA damage repair. The most severe type of damage in nuclear DNA is double-strand breaks (DSBs) which may be repaired via either non-homologous end joining (NHEJ) or homologous recombination (HR). In this review, we will summarize the basic features, the mechanisms, and the key players of both repair modes in plants with a focus on the model plant Arabidopsis thaliana. NHEJ may result in insertion of sequences from elsewhere in the genome but is much more often associated with deletions. If more than one DSB is processed simultaneously via NHEJ, besides deletions, inversions or translocations may also arise. As the germ line is only set aside late in plant development, somatic changes may be transferred to the next generation. Thus, NHEJ might influence the evolution of plant genomes and indeed seems to be an important factor of genome shrinking. Deletions may also be due to DSB-induced recombination between tandem duplicated homologous sequences by single-strand annealing (SSA). Moreover, conservative HR using the synthesis-dependent strand annealing (SDSA) mechanism operates in somatic plant cells. The efficiency of SDSA is dependent on the genomic template used as matrix for the repair of the DSB. Besides DSBs, stalled replication forks may also be processed via HR. Several DNA processing enzymes are involved in the regulation of replication initiated HR, mostly in its suppression, and we summarize the current knowledge of these processes in plants. PMID:24788060

Knoll, Alexander; Fauser, Friedrich; Puchta, Holger

2014-06-01

339

Developmental regulation of glial cell phagocytic function during Drosophila embryogenesis.  

PubMed

The proper removal of superfluous neurons through apoptosis and subsequent phagocytosis is essential for normal development of the central nervous system (CNS). During Drosophila embryogenesis, a large number of apoptotic neurons are efficiently engulfed and degraded by phagocytic glia. Here we demonstrate that glial proficiency to phagocytose relies on expression of phagocytic receptors for apoptotic cells, SIMU and DRPR. Moreover, we reveal that the phagocytic ability of embryonic glia is established as part of a developmental program responsible for glial cell fate determination and is not triggered by apoptosis per se. Explicitly, we provide evidence for a critical role of the major regulators of glial identity, gcm and repo, in controlling glial phagocytic function through regulation of SIMU and DRPR specific expression. Taken together, our study uncovers molecular mechanisms essential for establishment of embryonic glia as primary phagocytes during CNS development. PMID:25046770

Shklyar, Boris; Sellman, Yael; Shklover, Jeny; Mishnaevski, Ketty; Levy-Adam, Flonia; Kurant, Estee

2014-09-15

340

Differential expression of two scribble isoforms during Drosophila embryogenesis.  

PubMed

The tumour suppressor gene scribble (scrib) is required for epithelial polarity and growth control in Drosophila. Here, we report the identification and embryonic expression pattern of two Scrib protein isoforms resulting from alternative splicing during scrib transcription. Both proteins are first ubiquitously expressed during early embryogenesis. Then, during morphogenesis each Scrib protein displays a specific pattern of expression in the central and peripheral nervous systems, CNS and PNS, respectively. During germ band extension, the expression of the longer form Scrib1 occurs predominantly in the neuroblasts derived from the neuro-ectoderm and becomes later restricted to CNS neurones as well as to the pole cells in the gonads. By contrast, the shorter form Scrib2 is strongly expressed in the PNS and a subset of CNS neurones. PMID:11578873

Li, M; Marhold, J; Gatos, A; Török, I; Mechler, B M

2001-10-01

341

Effect of drilling muds on embryogenesis of the rainbow trout  

SciTech Connect

We studied the effect of three drilling muds on the early developmental stages of the rainbow trout. The following parameters were examined in the experiments: embryo mortality rate, rate of development, time of the beginning and end of individual stages and the duration embryogenesis on the whole, presence of developmental abnormalities, timing of larval hatching and morphometric indices of the larvae. Minimal inhibitory concentrations of the drilling muds were determined. The gel-humate drilling mud was the most toxic. At its level equal to 0.1-5.0 g/liter significant dose-dependent inhibition of their linear growth rate and the rate of weight increase, was found despite the high survival rate of the larvae. 4 refs., 7 tabs.

Kosheleva, V.V.; Novikov, M.A.; Migalovskii, I.P.

1994-09-01

342

Dance and Somatic Inquiry in Studios and Community Dance Programs.  

ERIC Educational Resources Information Center

Addresses pragmatic aspects of somatics in the public sector, investigating the fit of somatics within various institutions and settings, including universities, professional schools, and community programs. The article explores issues such as somatic movement approaches, certification, academic degrees in somatic study, confusions within the…

Eddy, Martha Hart

2002-01-01

343

Living in Movement: Development of Somatic Practices in Different Cultures.  

ERIC Educational Resources Information Center

Provides a transcultural perspective on somatics, reflecting on the evolution of somatics in different dance communities around the world, noting shifts that have occurred within specific cultural contexts, and discussing the presence of somatics in academia with the challenge of conducting research that retains somatic integrity. The article…

Fortin, Sylvie

2002-01-01

344

Stress and Somatic Complaints in Low-Income Urban Adolescents.  

ERIC Educational Resources Information Center

Studied rates of somatic complaints and the association between stress and somatic complaints for 1,030 low-income urban adolescents in grades 6 through 8. For both boys and girls, somatization was the most commonly reported internalizing symptom, and heightened rates of urban stress predicted heightened rates of somatic complaints. (SLD)

Reynolds, Linda K.; O'Koon, Jeffrey H.; Papademetriou, Eros; Szczygiel, Sylvia; Grant, Kathryn E.

2001-01-01

345

Cell wall components and pectin esterification levels as markers of proliferation and differentiation events during pollen development and pollen embryogenesis in Capsicum annuum L.  

PubMed Central

Plant cell walls and their polymers are regulated during plant development, but the specific roles of their molecular components are still unclear, as well as the functional meaning of wall changes in different cell types and processes. In this work the in situ analysis of the distribution of different cell wall components was performed during two developmental programmes, gametophytic pollen development, which is a differentiation process, and stress-induced pollen embryogenesis, which involves proliferation followed by differentiation processes. The changes in cell wall polymers were compared with a system of plant cell proliferation and differentiation, the root apical meristem. The analysis was also carried out during the first stages of zygotic embryogenesis. Specific antibodies recognizing the major cell wall polymers, xyloglucan (XG) and the rhamnogalacturonan II (RGII) pectin domain, and antibodies against high- and low-methyl-esterified pectins were used for both dot-blot and immunolocalization with light and electron microscopy. The results showed differences in the distribution pattern of these molecular complexes, as well as in the proportion of esterified and non-esterified pectins in the two pollen developmental pathways. Highly esterified pectins were characteristics of proliferation, whereas high levels of the non-esterified pectins, XG and RGII were abundant in walls of differentiating cells. Distribution patterns similar to those of pollen embryos were found in zygotic embryos. The wall changes reported are characteristic of proliferation and differentiation events as markers of these processes that take place during pollen development and embryogenesis. PMID:20097842

Bárány, Ivett; Fadón, Begoña; Risueño, María C.; Testillano, Pilar S.

2010-01-01

346

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, Øystein; 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.; Børresen-Dale, Anne-Lise; Lee, Ming Ta Michael; Wong, Bernice Huimin; Tan, Benita Kiat Tee; Hooijer, Gerrit K.J.

2014-01-01

347

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

348

Progress in the reprogramming of somatic cells.  

PubMed

Pluripotent stem cells can differentiate into nearly all types of cells in the body. This unique potential provides significant promise for cell-based therapies to restore tissues or organs destroyed by injuries, degenerative diseases, aging, or cancer. The discovery of induced pluripotent stem cell (iPSC) technology offers a possible strategy to generate patient-specific pluripotent stem cells. However, because of concerns about the specificity, efficiency, kinetics, and safety of iPSC reprogramming, improvements or fundamental changes in this process are required before their effective clinical use. A chemical approach is regarded as a promising strategy to improve and change the iPSC process. Dozens of small molecules have been identified that can functionally replace reprogramming factors and significantly improve iPSC reprogramming. In addition to the prospect of deriving patient-specific tissues and organs from iPSCs, another attractive strategy for regenerative medicine is transdifferentiation-the direct conversion of one somatic cell type to another. Recent studies revealed a new paradigm of transdifferentiation: using transcription factors used in iPSC generation to induce transdifferentiation or called iPSC transcription factor-based transdifferentiation. This type of transdifferentiation not only reveals and uses the developmentally plastic intermediates generated during iPSC reprogramming but also produces a wide range of cells, including expandable tissue-specific precursor cells. Here, we review recent progress of small molecule approaches in the generation of iPSCs. In addition, we summarize the new concept of iPSC transcription factor-based transdifferentiation and discuss its application in generating various lineage-specific cells, especially cardiovascular cells. PMID:23371904

Ma, Tianhua; Xie, Min; Laurent, Timothy; Ding, Sheng

2013-02-01

349

(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

350

Somatic Cell Nuclear Transfer (SCNT) in Mammals  

Microsoft Academic Search

It is now more than nine years since Dolly, the world’s first somatic cell cloned mammal was born, and the success of somatic\\u000a cell nuclear transfer (SCNT) is still disappointingly low. Only about 3–5% of reconstructed embryos develop to term, and it\\u000a is also evident that even if some clones are born, they are not necessarily fully developed and healthy.

Josef Fulka; Helena Fulka

351

Embryogenesis and production of albino plants from cell cultures of Bromus inermis.  

PubMed

Embryogenesis occurs in cells from brome grass grown in suspension culture in defined medium. Exogenous hormones are not required. The embryos develop into plants which lack chlorophyll. PMID:24497150

Gamborg, O L; Constabel, F; Miller, R A

1970-12-01

352

Identification of Spectral Modifications Occurring during Reprogramming of Somatic Cells  

PubMed Central

Recent technological advances in cell reprogramming by generation of induced pluripotent stem cells (iPSC) offer major perspectives in disease modelling and future hopes for providing novel stem cells sources in regenerative medicine. However, research on iPSC still requires refining the criteria of the pluripotency stage of these cells and exploration of their equivalent functionality to human embryonic stem cells (ESC). We report here on the use of infrared microspectroscopy to follow the spectral modification of somatic cells during the reprogramming process. We show that induced pluripotent stem cells (iPSC) adopt a chemical composition leading to a spectral signature indistinguishable from that of embryonic stem cells (ESC) and entirely different from that of the original somatic cells. Similarly, this technique allows a distinction to be made between partially and fully reprogrammed cells. We conclude that infrared microspectroscopy signature is a novel methodology to evaluate induced pluripotency and can be added to the tests currently used for this purpose. PMID:22514597

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

2012-01-01

353

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

354

An unusual split Drosophila heat shock gene expressed during embryogenesis, pupation and in testis.  

PubMed

Gene 2, one of the seven heat shock genes from locus 67B of Drosophila melanogaster, is transcribed into two polyadenylated RNAs having different developmental profiles of expression. The smaller transcript, of about 560 nucleotides, is expressed from mid-embryogenesis to the first two larval stages and again at the beginning of pupation. The larger transcript, 780 nucleotides, contains an additional 5' exon, accounting for its larger size. It is detected in pupae and adults, is male-specific and is localized in the testes. Heat shock does not affect the abundance of these two transcripts but induces the accumulation of a third RNA species of about 2000 nucleotides. This heat-shock RNA has the same cap site as the embryonic transcript, while its 3' portion entirely includes the neighbouring hsp22 gene. It appears, therefore, that in this case, heat shock alters the normal transcription termination process. By contrast to most heat shock genes, gene 2 contains several micro introns. One long open reading frame common to the three transcripts encodes a putative polypeptide of 111 amino acid residues. No homology was found with the other small heat shock genes of locus 67B. PMID:2454316

Pauli, D; Tonka, C H; Ayme-Southgate, A

1988-03-01

355

Reprogramming of murine and human somatic cells using a single polycistronic vector  

E-print Network

for the generation of patient-specific stem cells with the potential to bypass both the practical and ethical concerns associated with somatic cell nuclear transfer (SCNT) and human embryonic stem (hES) cells. Although the generation of induced pluripotent stem (iPS) cells has proven a robust technology in mouse

Saha, Krishanu

356

Donor-host mitochondrial compatibility improves efficiency of bovine somatic cell nuclear transfer  

Microsoft Academic Search

BACKGROUND: The interaction between the karyoplast and cytoplast plays an important role in the efficiency of somatic cell nuclear transfer (SCNT), but the underlying mechanism remains unclear. It is generally accepted that in nuclear transfer embryos, the reprogramming of gene expression is induced by epigenetic mechanisms and does not involve modifications of DNA sequences. In cattle, oocytes with various mitochondrial

Zhong-hai Yan; Yi-ye Zhou; Jing Fu; Fei Jiao; Lei-wen Zhao; Peng-fei Guan; Shu-zhen Huang; Yi-tao Zeng; Fanyi Zeng

2010-01-01

357

Vitamin C enhances in vitro and in vivo development of porcine somatic cell nuclear transfer embryos  

Microsoft Academic Search

The reprogramming of differentiated cells into a totipotent embryonic state through somatic cell nuclear transfer (SCNT) is still an inefficient process. Previous studies revealed that the generation of induced pluripotent stem (iPS) cells from mouse and human fibroblasts could be significantly enhanced with vitamin C treatment. Here, we investigated the effects of vitamin C, to our knowledge for the first

Yongye Huang; Xiaochun Tang; Wanhua Xie; Yan Zhou; Dong Li; Yang Zhou; Jianguo Zhu; Ting Yuan; Liangxue Lai; Daxin Pang; Hongsheng Ouyang

2011-01-01

358

Reprogramming following somatic cell nuclear transfer in primates is dependent upon nuclear remodeling  

Microsoft Academic Search

BACKGROUND: Somatic cell nuclear transfer (SCNT) requires cytoplast-mediated reprogramming of the donor nucleus. Cytoplast factors such as maturation promoting factor are implicated based on their involvement in nuclear envelope breakdown (NEBD) and premature chromosome condensation (PCC). Given prior difficulties in SCNT in primates using conventional protocols, we hypothesized that the ability of cytoplasts to induce nuclear remo- deling was instrumental

S. M. Mitalipov; Q. Zhou; J. A. Byrne; W. Z. Ji; R. B. Norgren; D. P. Wolf

2007-01-01

359

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

360

A simple consensus approach improves somatic mutation prediction accuracy  

PubMed Central

Differentiating true somatic mutations from artifacts in massively parallel sequencing data is an immense challenge. To develop methods for optimal somatic mutation detection and to identify factors influencing somatic mutation prediction accuracy, we validated predictions from three somatic mutation detection algorithms, MuTect, JointSNVMix2 and SomaticSniper, by Sanger sequencing. Full consensus predictions had a validation rate of >98%, but some partial consensus predictions validated too. In cases of partial consensus, read depth and mapping quality data, along with additional prediction methods, aided in removing inaccurate predictions. Our consensus approach is fast, flexible and provides a high-confidence list of putative somatic mutations. PMID:24073752

2013-01-01

361

Embryogenesis, morphogens and cancer stem cells: putting the puzzle together.  

PubMed

This paper describes a model which puts together three key elements of cancer theory: the analogies between embryogenesis and carcinogenesis, the role played in both processes by morphogens and related pathways, and the recently emerged paradigm of cancer stem cells. The model is called Epigenetic Tracking. Originally conceived as a model of embryonic development, it was later extended to interpret other aspects of biology, such as the presence of junk DNA, the phenomenon of ageing and the process of cancer formation. In this work we deepen our vision of carcinogenesis, and propose a novel hypothesis on the role of morphogen-processing pathways. According to the hypothesis, the interplay of these pathways leads in stem cells to the production of new transcription factors, which act as drivers of cellular differentiation. The disruption of these pathways, caused by mutations in specific genes, would represent the first and most distinctive event in the carcinogenic process. Our hypothesis allows us to make testable predictions on patterns of gene mutations involved in carcinogenesis. Our hypothesis also suggests that cancer stem cells can stay dormant until they are activated in a process that resembles activation of stem cells during tissue repair or at a specific time during development. PMID:23932050

Fontana, Alessandro; Wróbel, Borys

2013-10-01

362

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

363

The ?-tocopherol transfer protein is essential for vertebrate embryogenesis.  

PubMed

The hepatic ?-tocopherol transfer protein (TTP) is required for optimal ?-tocopherol bioavailability in humans; mutations in the human TTPA gene result in the heritable disorder ataxia with vitamin E deficiency (AVED, OMIM #277460). TTP is also expressed in mammalian uterine and placental cells and in the human embryonic yolk-sac, underscoring TTP's significance during fetal development. TTP and vitamin E are essential for productive pregnancy in rodents, but their precise physiological role in embryogenesis is unknown. We hypothesize that TTP is required to regulate delivery of ?-tocopherol to critical target sites in the developing embryo. We tested to find if TTP is essential for proper vertebrate development, utilizing the zebrafish as a non-placental model. We verify that TTP is expressed in the adult zebrafish and its amino acid sequence is homologous to the human ortholog. We show that embryonic transcription of TTP mRNA increases >7-fold during the first 24 hours following fertilization. In situ hybridization demonstrates that Ttpa transcripts are localized in the developing brain, eyes and tail bud at 1-day post fertilization. Inhibiting TTP expression using oligonucleotide morpholinos results in severe malformations of the head and eyes in nearly all morpholino-injected embryos (88% compared with 5.6% in those injected with control morpholinos or 1.7% in non-injected embryos). We conclude that TTP is essential for early development of the vertebrate central nervous system. PMID:23077608

Miller, Galen W; Ulatowski, Lynn; Labut, Edwin M; Lebold, Katie M; Manor, Danny; Atkinson, Jeffrey; Barton, Carrie L; Tanguay, Robert L; Traber, Maret G

2012-01-01

364

Further evidence that sperm nuclear proteins are necessary for embryogenesis.  

PubMed

We have recently presented evidence that the structural integrity of the mouse sperm nuclear matrix may be necessary for the proper unpackaging of sperm DNA for participation in embryogenesis. It is likely that the sperm nuclear matrix contributes to the organisation of the sperm DNA and its disturbance can seriously damage the paternal genome or its expression. In this work, we confirm our previous data and further suggest that even very subtle changes in the sperm nuclear structure may have a significant impact on embryo development. As reported previously, dithiothreitol (DTT) in the presence of an ionic detergent, ATAB, destabilized the nuclear matrix as measured by the halo assay, and oocytes injected with these nuclei failed to develop. We also discovered that omitting the protease inhibitor PMSF from the buffers used to extract spermatozoa prevented sperm injected into oocytes from participating in development. The organization of DNA into loop domains by the nuclear matrix in these nuclei appeared normal, as measured by the halo assay. Oocytes injected with sperm nuclei that had been washed with ATAB in the presence of phenylmethylsulphonyl fluoride (PMSF) but in the absence of DTT resulted in live births. Neither DTT treatment nor the absence of PMSF would be expected to disrupt the integrity of the paternal DNA. The data therefore suggest that even very subtle alterations in the structural proteins of the nucleus are enough to deprive sperm DNA of the ability to contribute to embryonic development. PMID:10840874

Ward, W S; Kishikawa, H; Akutsu, H; Yanagimachi, H; Yanagimachi, R

2000-02-01

365

Reevaluation of the Reliability and Usefulness of the Somatic Homologous Recombination Reporter Lines  

PubMed Central

A widely used approach for assessing genome instability in plants makes use of somatic homologous recombination (SHR) reporter lines. Here, we review the published characteristics and uses of SHR lines. We found a lack of detailed information on these lines and a lack of sufficient evidence that they report only homologous recombination. We postulate that instead of SHR, these lines might be reporting a number of alternative stress-induced stochastic events known to occur at transcriptional, posttranscriptional, and posttranslational levels. We conclude that the reliability and usefulness of the somatic homologous recombination reporter lines requires revision. Thus, more detailed information about these reporter lines is needed before they can be used with confidence to measure genome instability, including the complete sequences of SHR constructs, the genomic location of reporter genes and, importantly, molecular evidence that reconstituted gene expression in these lines is indeed a result of somatic recombination. PMID:23144181

Ulker, Bekir; Hommelsheim, Carl Maximilian; Berson, Tobias; Thomas, Stefan; Chandrasekar, Balakumaran; Olcay, Ahmet Can; Berendzen, Kenneth Wayne; Frantzeskakis, Lamprinos

2012-01-01

366

Sweetpotato late embryogenesis abundant 14 ( IbLEA14 ) gene influences lignification and increases osmotic- and salt stress-tolerance of transgenic calli  

Microsoft Academic Search

Late embryogenesis abundant 14 (LEA14) cDNA was isolated from an EST library prepared from dehydration-treated fibrous roots of sweetpotato (Ipomoea batatas). Quantitative RT-PCR revealed a variety of different IbLEA14 expression patterns under various abiotic stress conditions. IbLEA14 expression was strongly induced by dehydration, NaCl and abscisic acid treatments in sweetpotato plants. Transgenic sweetpotato\\u000a non-embryogenic calli harboring IbLEA14 overexpression or RNAi

Sung-Chul Park; Yun-Hee Kim; Jae Cheol Jeong; Cha Young Kim; Haeng-Soon Lee; Jae-Wook Bang; Sang-Soo Kwak

2011-01-01

367

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

368

Somatic cell counts of ewes' milk.  

PubMed

The somatic cell counts of ewes' milk were determined by an electronic particle counter (Coulter Counter). Of 1408 apparently normal milk samples, 98.2% had a somatic cell count lower than 1.0 x 10(6) cells/ml and 85.8% of 254 bacteriologically positive samples had a count higher than 1.0 x 10(6) cells/ml. Values exceeding 1.0 x 10(6) cells/ml are indicative of subclinical mastitis, if samples were collected from clinically healthy mammary glands. PMID:1777802

Fthenakis, G C; el-Masannat, E T; Booth, J M; Jones, J E

1991-01-01

369

Demethylation of somatic and testis-specific histone H2A and H2B genes in F9 embryonal carcinoma cells.  

PubMed Central

In contrast to many other genes containing a CpG island, the testis-specific H2B (TH2B) histone gene exhibits tissue-specific methylation patterns in correlation with gene activity. Characterization of the methylation patterns within a 20-kb segment containing the TH2A and TH2B genes in comparison with that in a somatic histone cluster revealed that: (i) the germ cell-specific unmethylated domain of the TH2A and TH2B genes is defined as a small region surrounding the CpG islands of the TH2A and TH2B genes and (ii) somatic histone genes are unmethylated in both liver and germ cells, like other genes containing CpG islands, whereas flanking sequences are methylated. Transfection of in vitro-methylated TH2B, somatic H2B, and mouse metallothionein I constructs into F9 embryonal carcinoma cells revealed that the CpG islands of the TH2A and TH2B genes were demethylated like those of the somatic H2A and H2B genes and the metallothionein I gene. The demethylation of those CpG islands became significantly inefficient at a high number of integrated copies and a high density of methylated CpG dinucleotides. In contrast, three sites in the somatic histone cluster, of which two sites are located in the long terminal repeat of an endogenous retrovirus-like sequence, were efficiently demethylated even at a high copy number and a high density of methylated CpG dinucleotides. These results suggest two possible mechanisms for demethylation in F9 cells and methylation of CpG islands of the TH2A and TH2B genes at the postblastula stage during embryogenesis. Images PMID:8355699

Choi, Y C; Chae, C B

1993-01-01

370

Regional specification during embryogenesis in the inarticulate brachiopod Glottidia.  

PubMed

A fate map has been constructed for the lingulid brachiopod Glottidia pyramidata. The animal half of the egg forms part of the apical lobe and the dorsal valve of the larva. The vegetal half of the egg forms mesoderm and endoderm and is the site of gastrulation; it also forms part of the apical lobe and the ventral valve of the larva. The plane of the first cleavage goes through the animal-vegetal axis of the egg along the future plane of bilateral symmetry of the larva. The timing of regional specification in these embryos was examined by isolating animal or vegetal, anterior or posterior, or lateral regions at different times from prior to fertilization through gastrulation. Animal halves isolated at all stages formed an epithelial vesicle and did not gastrulate. When these halves were isolated from unfertilized eggs or early cleavage stage embryos, they usually did not form an apical lobe or valve; however, when the halves were isolated at later developmental stages, these structures differentiated in a high frequency of cases. Vegetal halves were isolated at all stages gastrulated and formed a larva; however, when these halves were isolated at gastrulation they frequently lacked a dorsal valve. When lateral cuts were made along the animal-vegetal axis at all developmental stages, both halves gastrulated. When the cut was made perpendicular to the plane of the first cleavage from the four-cell stage on, one-half formed the anterior end and the other half formed the posterior end of the larva. These results suggest that there are localized determinants in the egg that specify the different regions of the larva, but there is also an inductive signal(s) from the vegetal region of the embryo that is necessary in order for cells that inherit a given determinant to differentiate. Embryogenesis in Glottidia is compared with articulate brachiopods and phoronids. PMID:7589795

Freeman, G

1995-11-01

371

Cloning animals by somatic cell nuclear transfer – biological factors  

Microsoft Academic Search

Cloning by nuclear transfer using mammalian somatic cells has enormous potential application. However, somatic cloning has been inefficient in all species in which live clones have been produced. High abortion and fetal mortality rates are commonly observed. These developmental defects have been attributed to incomplete reprogramming of the somatic nuclei by the cloning process. Various strategies have been used to

X Cindy Tian; Chikara Kubota; Brian Enright; Xiangzhong Yang

2003-01-01

372

Somatic Disorders of Childhood and Adolescence.  

ERIC Educational Resources Information Center

Briefly reviews number of theories which address role of psychological factors in etiology of somatic disorders. Focuses on psychological treatment approaches that have been used to alleviate or reduce symptomatic behaviors associated with eating disorders, elimination disorders, and headaches in children. Discusses role of school psychologists in…

Siegel, Lawrence J.

1990-01-01

373

Psychosomatic Syndromes, Somatization and Somatoform Disorders  

Microsoft Academic Search

A psychosomatic syndrome is defined as a syndrome in which psychological processes play a substantial role in the etiology of the illness in some of the patients. The main conclusions on the extent of the biological and psychosocial contributions to several psychosomatic syndromes are presented and the relationship of these syndromes to somatization and somatoform disorders is discussed. The syndromes

Robert Kellner

1994-01-01

374

Somatic Cell Cloning in Polyester Stacks  

Microsoft Academic Search

Single somatic cells, including fibroblasts, myelomas, and hybridomas, proliferate normally when trapped between a plastic dish and a disc of polyester cloth. Contact between the overlay and the plastic for 8-16 days results in identical colony patterns on the cloth and the plate. When several cloth discs are simultaneously stacked over Chinese hamster ovary cells, three or four high-resolution colony

Christian R. H. Raetz; Mary M. Wermuth; Thomas M. McIntyre; Jeffrey D. Esko; Debra C. Wing

1982-01-01

375

Interspecies Somatic Cell Nuclear Transfer: Advancements and Problems  

PubMed Central

Abstract Embryologists working with livestock species were the pioneers in the field of reprogramming by somatic cell nuclear transfer (SCNT). Without the “Dolly experiment,” the field of cellular reprogramming would have been slow and induced plutipotent cells (iPSCs) would not have been conceived. The major drive of the work in mammalian cloning was the interest of the breeding industry to propagate superior genotypes. Soon it was realized that the properties of oocytes could be used also to clone endangered mammalian species or to reprogram the genomes of unrelated species through what is known as interspecies (i) SCNT, using easily available oocytes of livestock species. iSCNT for cloning animals works only for species that can interbreed, and experiments with taxonomically distant species have not been successful in obtaining live births or deriving embryonic stem cell (ESC) lines to be used for regenerative medicine. There are controversial reports in the literature, but in most cases these experiments have underlined some of the cellular and molecular mechanisms that are incomplete during cell nucleus reprogramming, including the failure to organize nucleoli, silence somatic cell genes, activate the embryonic genome, and resume mitochondrial replication and function, thus indicating nucleus–cytoplasmic incompatibility. PMID:24033141

Lagutina, Irina; Fulka, Helena; Lazzari, Giovanna

2013-01-01

376

In vivo Reprogramming of Adult Somatic Cells to Pluripotency by Overexpression of Yamanaka Factors  

PubMed Central

Induced pluripotent stem (iPS) cells that result from the reprogramming of somatic cells to a pluripotent state by forced expression of defined factors are offering new opportunities for regenerative medicine. Such clinical applications of iPS cells have been limited so far, mainly due to the poor efficiency of the existing reprogramming methodologies and the risk of the generated iPS cells to form tumors upon implantation. We hypothesized that the reprogramming of somatic cells towards pluripotency could be achieved in vivo by gene transfer of reprogramming factors. In order to efficiently reprogram cells in vivo, high levels of the Yamanaka (OKSM) transcription factors need to be expressed at the target tissue. This can be achieved by using different viral or nonviral gene vectors depending on the target tissue. In this particular study, hydrodynamic tail-vein (HTV) injection of plasmid DNA was used to deliver the OKSM factors to mouse hepatocytes. This provided proof-of-evidence of in vivo reprogramming of adult, somatic cells towards a pluripotent state with high efficiency and fast kinetics. Furthermore no tumor or teratoma formation was observed in situ. It can be concluded that reprogramming somatic cells in vivo may offer a potential approach to induce enhanced pluripotency rapidly, efficiently, and safely compared to in vitro performed protocols and can be applied to different tissue types in the future. PMID:24378537

Yilmazer, Acelya; de Lazaro, Irene; Bussy, Cyrill; Kostarelos, Kostas

2013-01-01

377

Animal Cell Differentiation Patterns Suppress Somatic Evolution  

E-print Network

Cell differentiation in multicellular organisms has the obvious function during development of creating new cell types. However, in long-lived organisms with extensive cell turnover, cell differentiation often continues after new cell types are no longer needed or produced. Here, we address the question of why this is true. It is believed that multicellular organisms could not have arisen or been evolutionarily stable without possessing mechanisms to suppress somatic selection among cells within organisms, which would otherwise disrupt organismal integrity. Here, we propose that one such mechanism is a specific pattern of ongoing cell differentiation commonly found in metazoans with cell turnover, which we call ‘‘serial differentiation.’ ’ This pattern involves a sequence of differentiation stages, starting with self-renewing somatic stem cells and proceeding through several (non–self-renewing) transient amplifying cell stages before ending with terminally differentiated cells. To test the hypothesis that serial differentiation can suppress somatic evolution, we used an agent-based computer simulation of cell population dynamics and evolution within tissues. The results indicate that, relative to other, simpler patterns, tissues organized into serial differentiation experience lower rates of detrimental cell-level evolution. Self-renewing cell populations are susceptible to somatic evolution, while those that are not self-renewing are not. We find that a mutation disrupting differentiation can create a new self-renewing cell population that is vulnerable to somatic evolution. These results are relevant not only to understanding the evolutionary origins of multicellularity, but also the causes of pathologies such as cancer and

Kathleen Sprouffske; Carlo C. Maley

378

Correction: Somatic mutations in cancer development  

PubMed Central

Since publication of Environmental Health 2011, 10(Suppl 1):S12 [1] it has been noticed that titles and captions for the figures and tables were incorrectly applied. In this full-length correction article, figures and tables have been renumbered with legends and captions applied appropriately. Some minor typographical errors have also been corrected. The inconvenience caused to readers by premature publication of the original paper is regretted. The transformation of a normal cell into a cancer cell takes place through a sequence of a small number of discrete genetic events, somatic mutations: thus, cancer can be regarded properly as a genetic disease of somatic cells. The analogy between evolution of organisms and evolution of cell populations is compelling: in both cases what drives change is mutation, but it is Darwinian selection that enables clones that have a growth advantage to expand, thus providing a larger target size for the next mutation to hit. The search for molecular lesions in tumors has taken on a new dimension thanks to two powerful technologies: the micro-arrays for quantitative analysis of global gene expresssion (the transcriptome); and ‘deep’ sequencing for the global analysis of the entire genome (or at least the exome). The former offers the most complete phenotypic characterization of a tumor we could ever hope for – we could call this the ultimate phenotype; the latter can identify all the somatic mutations in an individual tumor – we could call this the somatic genotype. However, there is definitely the risk that while we are ‘drowned by data, we remain thirsty for knowledge’. If we want to heed the teachings of Lorenzo Tomatis, I think the message is clear: we ought to take advantage of the new powerful technologies – not by becoming their slaves, but remaining their masters. Identifying somatic mutations in a tumor is important because through a deeper understanding of the nature of that particular tumor it can help us to optimize therapy or to design new therapeutic approaches.

2011-01-01

379

Somatization, heartsink patients, or functional somatic symptoms? Towards a clinical useful classification in primary health care.  

PubMed

Several definitions of somatization exist and try to deal with the fundamental problem that a large group of patients present with physical symptoms for which a conventional pathology cannot be identified. However, the concept remains somewhat confusing. The prevalence of somatization is high in general practice. Nevertheless, patients do not receive proper treatment and risk iatrogenic somatic fixation and harm, the doctor-patient relationship is often negatively affected and the overall healthcare system suffers from high expenditure on unnecessary physical investigations and treatments. During the last decade research has shown that somatization may be treated effectively in specialist care. Little is known about effective treatment in primary care but the Reattribution Model and the Extended Reattribution and Management Model have shown promising results. The development and evaluation of new treatment strategies is, however, hampered by the confusion of definitions and concepts. In this article an overview is presented of the various concepts relevant to the clinical work and research in primary health care. It is important to realize that somatizing patients in primary health care present a broader spectrum of severity than patients seen in a specialist setting. Hence, primary care cannot apply definitions from specialist care directly but needs a definition that also includes the mild cases. We need classifications and agreed definitions applicable in primary health care in order to develop appropriate management strategies, to predict prognosis, and to enable rigorous research concerning the large group of somatizing patients in primary health care. PMID:16025867

Rosendal, Marianne; Fink, Per; Bro, Flemming; Olesen, Frede

2005-03-01

380

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

PubMed Central

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

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

2013-01-01

381

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.

382

Zebrafish Noxa promotes mitosis in early embryonic development and regulates apoptosis in subsequent embryogenesis  

PubMed Central

Noxa functions in apoptosis and immune system of vertebrates, but its activities in embryo development remain unclear. In this study, we have studied the role of zebrafish Noxa (zNoxa) by using zNoxa-specifc morpholino knockdown and overexpression approaches in developing zebrafish embryos. Expression pattern analysis indicates that zNoxa transcript is of maternal origin, which displays a uniform distribution in early embryonic development until shield stage, and the zygote zNoxa transcription is initiated from this stage and mainly localized in YSL of the embryos. The zNoxa expression alterations result in strong embryonic development defects, demonstrating that zNoxa regulates apoptosis from 75% epiboly stage of development onward, in which zNoxa firstly induces the expression of zBik, and then cooperates with zBik to regulate apoptosis. Moreover, zNoxa knockdown also causes a reduction in number of mitotic cells before 8 h.p.f., suggesting that zNoxa also promotes mitosis before 75% epiboly stage. The effect of zNoxa on mitosis is mediated by zWnt4b in early embryos, whereas zMcl1a and zMcl1b suppress the ability of zNoxa to regulate mitosis and apoptosis at different developmental stages. In addition, mammalian mouse Noxa (mNoxa) mRNA was demonstrated to rescue the arrest of mitosis when zNoxa was knocked down, suggesting that mouse and zebrafish Noxa might have similar dual functions. Therefore, the current findings indicate that Noxa is a novel regulator of early mitosis before 75% epiboly stage when it translates into a key mediator of apoptosis in subsequent embryogenesis. PMID:24608793

Zhong, J-X; Zhou, L; Li, Z; Wang, Y; Gui, J-F

2014-01-01

383

LEA (Late Embryogenesis Abundant) proteins and their encoding genes in Arabidopsis thaliana  

PubMed Central

Background LEA (late embryogenesis abundant) proteins have first been described about 25 years ago as accumulating late in plant seed development. They were later found in vegetative plant tissues following environmental stress and also in desiccation tolerant bacteria and invertebrates. Although they are widely assumed to play crucial roles in cellular dehydration tolerance, their physiological and biochemical functions are largely unknown. Results We present a genome-wide analysis of LEA proteins and their encoding genes in Arabidopsis thaliana. We identified 51 LEA protein encoding genes in the Arabidopsis genome that could be classified into nine distinct groups. Expression studies were performed on all genes at different developmental stages, in different plant organs and under different stress and hormone treatments using quantitative RT-PCR. We found evidence of expression for all 51 genes. There was only little overlap between genes expressed in vegetative tissues and in seeds and expression levels were generally higher in seeds. Most genes encoding LEA proteins had abscisic acid response (ABRE) and/or low temperature response (LTRE) elements in their promoters and many genes containing the respective promoter elements were induced by abscisic acid, cold or drought. We also found that 33% of all Arabidopsis LEA protein encoding genes are arranged in tandem repeats and that 43% are part of homeologous pairs. The majority of LEA proteins were predicted to be highly hydrophilic and natively unstructured, but some were predicted to be folded. Conclusion The analyses indicate a wide range of sequence diversity, intracellular localizations, and expression patterns. The high fraction of retained duplicate genes and the inferred functional diversification indicate that they confer an evolutionary advantage for an organism under varying stressful environmental conditions. This comprehensive analysis will be an important starting point for future efforts to elucidate the functional role of these enigmatic proteins. PMID:18318901

Hundertmark, Michaela; Hincha, Dirk K

2008-01-01

384

Reprogramming to Pluripotency through a Somatic Stem Cell Intermediate  

PubMed Central

Transcription factor-based reprogramming can lead to the successful switching of cell fates. We have recently reported that mouse embryonic fibroblasts (MEFs) can be directly reprogrammed into induced neural stem cells (iNSCs) after the forced expression of Brn4, Sox2, Klf4, and Myc. Here, we tested whether iNSCs could be further reprogrammed into induced pluripotent stem cells (iPSCs). The two factors Oct4 and Klf4 were sufficient to induce pluripotency in iNSCs. Immunocytochemistry and gene expression analysis showed that iNSC-derived iPSCs (iNdiPSCs) are similar to embryonic stem cells at the molecular level. In addition, iNdiPSCs could differentiate into cells of all three germ layers, both in vitro and in vivo, proving that iNdiPSCs are bona fide pluripotent cells. Furthermore, analysis of the global gene expression profile showed that iNdiPSCs, in contrast to iNSCs, do not retain any MEF transcriptional memory even at early passages after reprogramming. Overall, our results demonstrate that iNSCs can be reprogrammed to pluripotency and suggest that cell fate can be redirected numerous times. Importantly, our findings indicate that the induced pluripotent cell state may erase the donor-cell type epigenetic memory more efficiently than other induced somatic cell fates. PMID:24386457

Marthaler, Adele G.; Tiemann, Ulf; Arauzo-Bravo, Marcos J.; Wu, Guangming; Zaehres, Holm; Hyun, Jung Keun; Han, Dong Wook; Scholer, Hans R.; Tapia, Natalia

2013-01-01

385

Delivering Factors for Reprogramming a Somatic Cell to Pluripotency  

PubMed Central

An adult cell originates from stem cell. The stem cell is usually categorized into three species including an embryonic stem cell (ESc), an adult stem cell, and an induced stem cell (iPSc). iPSc features pluripotency, which is meant to be differentiated into any types of cells. Accordingly, it is much attractive to anyone who pursuit a regenerative medicine, owing to the potential almighty. They are simply produced by reprogramming a somatic cell via a transfer of transcription factors. The efficiency and productivity of iPS are considerably subject to delivering methods of exogenous genes into a variety of targeted mammalians. Conventional and well-run gene delivery techniques have been reviewed here. This details the methods and principles of delivery factors and provides an overview of the research, with an emphasis on their potential for use as clinical therapeutic platforms. PMID:24298349

Um, Soong Ho

2012-01-01

386

Glucose 6-phosphate dehydrogenase deficiency enhances germ cell apoptosis and causes defective embryogenesis in Caenorhabditis elegans  

PubMed Central

Glucose 6-phosphate dehydrogenase (G6PD) deficiency, known as favism, is classically manifested by hemolytic anemia in human. More recently, it has been shown that mild G6PD deficiency moderately affects cardiac function, whereas severe G6PD deficiency leads to embryonic lethality in mice. How G6PD deficiency affects organisms has not been fully elucidated due to the lack of a suitable animal model. In this study, G6PD-deficient Caenorhabditis elegans was established by RNA interference (RNAi) knockdown to delineate the role of G6PD in animal physiology. Upon G6PD RNAi knockdown, G6PD activity was significantly hampered in C. elegans in parallel with increased oxidative stress and DNA oxidative damage. Phenotypically, G6PD-knockdown enhanced germ cell apoptosis (2-fold increase), reduced egg production (65% of mock), and hatching (10% of mock). To determine whether oxidative stress is associated with G6PD knockdown-induced reproduction defects, C. elegans was challenged with a short-term hydrogen peroxide (H2O2). The early phase egg production of both mock and G6PD-knockdown C. elegans were significantly affected by H2O2. However, H2O2-induced germ cell apoptosis was more dramatic in mock than that in G6PD-deficient C. elegans. To investigate the signaling pathways involved in defective oogenesis and embryogenesis caused by G6PD knockdown, mutants of p53 and mitogen-activated protein kinase (MAPK) pathways were examined. Despite the upregulation of CEP-1 (p53), cep-1 mutation did not affect egg production and hatching in G6PD-deficient C. elegans. Neither pmk-1 nor mek-1 mutation significantly affected egg production, whereas sek-1 mutation further decreased egg production in G6PD-deficient C. elegans. Intriguingly, loss of function of sek-1 or mek-1 dramatically rescued defective hatching (8.3- and 9.6-fold increase, respectively) induced by G6PD knockdown. Taken together, these findings show that G6PD knockdown reduces egg production and hatching in C. elegans, which are possibly associated with enhanced oxidative stress and altered MAPK pathways, respectively. PMID:23640458

Yang, H-C; Chen, T-L; Wu, Y-H; Cheng, K-P; Lin, Y-H; Cheng, M-L; Ho, H-Y; Lo, S J; Chiu, D T-Y

2013-01-01

387

Chromatin repeat length in somatic hybrids.  

PubMed Central

In order to study the mechanisms by which a characteristic repeat length is inherited in somatic cells, it was necessary to develop a method for determining repeat length with a precision of 1 to 2 base pairs. Hybrid clones between parental cell lines differing in repeat length by 6 base pairs were isolated. The four independent hybrid clones characterized had repeat lengths intermediate between those of the parental lines; however, it could be demonstrated that these repeat lengths are unique values and do not arise from a double distribution of the parental repeat lengths. It therefore is concluded that repeat length in somatic cells is determined by a common pool of diffusible substances. Images PMID:6930661

Sperling, L; Tardieu, A; Weiss, M C

1980-01-01

388

Transformation of somatic cells into stem cell-like cells under a stromal niche  

PubMed Central

To study the genomic plasticity of somatic cells without ectopic genetic manipulation, we cultured mouse fibroblasts with ovarian cells, embryonic fibroblasts of different strains, and parthenogenetic embryonic stem cells (ESCs). Of 41 trials, cell aggregation resembling nascent ESC colony from inner cell mass was detected in 9 cases (22%), and 6 cases (67%) yielded fibroblast-derived colonies with ESC morphology. Cells used in coculture provided the critical (P=0.0061) inducing factor for the aggregation. These colony-forming fibroblasts (CFFs) showed similar characteristics to those in ESCs and induced pluripotent stem cells (iPSCs), including pluripotency gene expression, in vitro differentiation, and teratoma formation. Furthermore, CFFs produced somatic chimera, although none showed germline chimerism. CFFs had a tetraploid-like karyotype, and their imprinting patterns differed from parthenogenetic ESCs, thereby confirming their nongermline transmissibility. We observed dysregulation of cell cycle-related proteins, as well as both homologous and heterologous recombination of genomic single-nucleotide polymorphisms in CFFs. Our observations provide information on somatic cell plasticity, resulting in stemness or tumorigenesis, regardless of colony-forming cell progenitors in the fibroblast population. The plasticity of somatic genomes under environmental influences, as well as acquisition of pluripotency by cell fusion, is also implicated.—Lee, S. T., Gong, S. P., Yum, K. E., Lee, E. J., Lee, C. H., Choi, J. H., Kim, D. Y., Han, H., Kim, K.-S., Hysolli, E., Ahn, J. Y., Park, I.-H., Han, J. Y., Jeong, J.-W., Lim, J. M. Transformation of somatic cells into stem cell-like cells under a stromal niche. PMID:23580613

Lee, Seung Tae; Gong, Seung Pyo; Yum, Kyung Eun; Lee, Eun Ju; Lee, Chae Hyun; Choi, Jun Hee; Kim, Dae Yong; Han, Hojae; Kim, Kye-Seong; Hysolli, Eriona; Ahn, Ji Yeon; Park, In-Hyun; Han, Jae Yong; Jeong, Jae-Wook; Lim, Jeong Mook

2013-01-01

389

Hematopoietic Stem Cells and Somatic Stem Cells  

Microsoft Academic Search

\\u000a Stem cells are unspecialized cells that can differentiate to generate more specialized cell types responsible for tissue-specific\\u000a function. During development, the differentiation of pluripotent embryonic stem cells leads to the production of specialized\\u000a somatic cells that are ultimately responsible for the structure and function of all adult tissues and organs. “Naturally”\\u000a pluripotent cells exist only at the earliest stages of

Kah Yong Tan; Francis S. Kim; Amy J. Wagers; Shane R. Mayack

390

Somatic cell cloning in polyester stacks.  

PubMed Central

Single somatic cells, including fibroblasts, myelomas, and hybridomas, proliferate normally when trapped between a plastic dish and a disc of polyester cloth. Contact between the overlay and the plastic for 8-16 days results in identical colony patterns on the cloth and the plate. When several cloth discs are simultaneously stacked over Chinese hamster ovary cells, three or four-high resolution colony copies can be generated from a single master dish. The colonies on the cloth can be analyzed by radiochemical methods [Esko, J. D. & Raetz, C. R. H. (1978) Proc. Natl. Acad. Sci. USA 75, 1190-1193] or by "replica plating" to a new disc. The use of polyester cloth, singly or in stacks, has several major advantages over previous techniques for somatic cell replica plating, including: (i) broad applicability to diverse cell lines such as fragile membrane mutants of Chinese hamster ovary cells and relatively nonadherent myelomas or hybridomas; (ii) the possibility of generating multiple copies of the same colony population, allowing simultaneous analysis for several enzymes or cellular components; and (iii) superior resolution and transfer efficiency in copying colony patterns from one surface to another. The remarkable capacity of animal cell colonies to proliferate upward through "polyester stacks" may reflect chemotropic movement of individual cells and opens new approaches to somatic cell genetics. Images PMID:6954474

Raetz, C R; Wermuth, M M; McIntyre, T M; Esko, J D; Wing, D C

1982-01-01

391

Somatic Cell Nuclear Transfer in the Mouse  

NASA Astrophysics Data System (ADS)

Somatic cell nuclear transfer (SCNT) has become a unique and powerful tool for epigenetic reprogramming research and gene manipulation in animals since “Dolly,” the first animal cloned from an adult cell was reported in 1997. Although the success rates of somatic cloning have been inefficient and the mechanism of reprogramming is still largely unknown, this technique has been proven to work in more than 10 mammalian species. Among them, the mouse provides the best model for both basic and applied research of somatic cloning because of its abounding genetic resources, rapid sexual maturity and propagation, minimal requirements for housing, etc. This chapter describes a basic protocol for mouse cloning using cumulus cells, the most popular cell type for NT, in which donor nuclei are directly injected into the oocyte using a piezo-actuated micromanipulator. In particular, we focus on a new, more efficient mouse cloning protocol using trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, which increases both in vitro and in vivo developmental rates from twofold to fivefold. This new method including TSA will be helpful to establish mouse cloning in many laboratories.

Kishigami, Satoshi; Wakayama, Teruhiko

392

Identification in Pea Seed Mitochondria of a Late-Embryogenesis Abundant Protein Able to  

E-print Network

Identification in Pea Seed Mitochondria of a Late-Embryogenesis Abundant Protein Able to Protect) seed mitochondria. PsLEAm revealed typical LEA features such as high hydrophilicity and repeated motifs. The overall results constitute, to our knowledge, the first characterization of a LEA protein in mitochondria

Paris-Sud XI, Université de

393

Na,K-ATPase ? and ? subunit genes exhibit unique expression patterns during zebrafish embryogenesis  

Microsoft Academic Search

We have used in situ hybridization to analyze Na,K-ATPase ? and ? subunit gene expression during zebrafish embryogenesis. The most striking finding is that each of the 14 Na,K-ATPase genes exhibits a distinct expression profile. All ? and ? subunit genes are expressed in the nervous system, although the pattern of expression in different regions varies dramatically. In peripheral tissues,

Victor A Canfield; Benjamin Loppin; Bernard Thisse; Christine Thisse; John H Postlethwait; Manzoor-Ali P. K Mohideen; S. Johannes R Rajarao; Robert Levenson

2002-01-01

394

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

395

A mitochondrial late embryogenesis abundant protein stabilizes model membranes in the dry state  

Microsoft Academic Search

Late embryogenesis abundant (LEA) proteins are a highly diverse group of polypeptides expected to play important roles in desiccation tolerance of plant seeds. They are also found in other plant tissues and in some anhydrobotic invertebrates, fungi, protists and prokaryotes. The LEA protein LEAM accumulates in the matrix space of pea (Pisum sativum) mitochondria during late seed maturation. LEAM is

Dimitri Tolleter; Dirk K. Hincha; David Macherel

2010-01-01

396

LEA (Late Embryogenesis Abundant) proteins and their encoding genes in Arabidopsis thaliana  

Microsoft Academic Search

BACKGROUND: LEA (late embryogenesis abundant) proteins have first been described about 25 years ago as accumulating late in plant seed development. They were later found in vegetative plant tissues following environmental stress and also in desiccation tolerant bacteria and invertebrates. Although they are widely assumed to play crucial roles in cellular dehydration tolerance, their physiological and biochemical functions are largely

Michaela Hundertmark; Dirk K Hincha

2008-01-01

397

Determination of cell division axes in the early embryogenesis of Caenorhabditis elegans  

Microsoft Academic Search

The establishment of cell division axes was examined in the early embryonic divisions of Caenorhabditis elegans. It has been shown previously that there are two different patterns of cleavage during early embryogenesis. In one set of cells, which un- dergo predominantly determinative divisions, the divi- sion axes are established successively in the same orientation, while division axes in the other

Anthony A. Hyman; John G. White

1987-01-01

398

Outer Hair Cell Somatic Electromotility In Vivo and Power Transfer to the Organ of Corti  

PubMed Central

The active amplification of sound-induced vibrations in the cochlea, known to be crucial for auditory sensitivity and frequency selectivity, is not well understood. The outer hair cell (OHC) somatic electromotility is a potential mechanism for such amplification. Its effectiveness in vivo is putatively limited by the electrical low-pass filtering of the cell's transmembrane potential. However, the transmembrane potential is an incomplete metric. We propose and estimate two metrics to evaluate the effectiveness of OHC electromotility in vivo. One metric is the OHC electromechanical ratio defined as the amplitude of the ratio of OHC displacement to the change in its transmembrane potential. The in vivo electromechanical ratio is derived from the recently measured in vivo displacements of the reticular lamina and the basilar membrane at the 19 kHz characteristic place in guinea pigs and using a model. The ratio, after accounting for the differences in OHC vibration in situ due to the impedances from the adjacent structures, is in agreement with the literature values of the in vitro electromechanical ratio measured by others. The second and more insightful metric is the OHC somatic power. Our analysis demonstrates that the organ of Corti is nearly optimized to receive maximum somatic power in vivo and that the estimated somatic power could account for the active amplification. PMID:22325260

Ramamoorthy, Sripriya; Nuttall, Alfred L.

2012-01-01

399

Mouse SCNT ESCs Have Lower Somatic Mutation Load Than Syngeneic iPSCs.  

PubMed

Ectopic expression of reprogramming factors has been widely adopted to reprogram somatic nucleus into a pluripotent state (induced pluripotent stem cells [iPSCs]). However, genetic aberrations such as somatic gene mutation in the resulting iPSCs have raised concerns regarding their clinical utility. To test whether the increased somatic mutations are primarily the by-products of current reprogramming methods, we reprogrammed embryonic fibroblasts of inbred C57BL/6 mice into either iPSCs (8 lines, 4 previously published) or embryonic stem cells (ESCs) with somatic cell nuclear transfer (SCNT ESCs; 11 lines). Exome sequencing of these lines indicates a significantly lower mutation load in SCNT ESCs than iPSCs of syngeneic background. In addition, one SCNT-ESC line has no detectable exome mutation, and two pairs of SCNT-ESC lines only have shared preexisting mutations. In contrast, every iPSC line carries unique mutations. Our study highlights the need for improving reprogramming methods in more physiologically relevant conditions. PMID:24749065

Li, Zhe; Lu, Hongxia; Yang, Weifeng; Yong, Jun; Zhang, Zhen-Ning; Zhang, Kun; Deng, Hongkui; Xu, Yang

2014-04-01

400

Somatosensory Pulsatile Tinnitus Syndrome: Somatic Testing Identifies a Pulsatile Tinnitus Subtype That Implicates the Somatosensory System  

PubMed Central

A new tinnitus syndrome is described: high-pitched, cardiac-synchronous tinnitus, whose pulsations are suppressed by strong contractions or compressions of the neck and jaw muscles (somatic testing). 14 cases, 6 non-lateralized and 8 unilateral, are reported. In the non-lateralized cases, onset was bilateral. In the one intermittent case, while her tinnitus was absent her pulsatile tinnitus could be induced by somatic testing. No etiology was found from physical examination, imaging, or ancillary testing. Because these cases of pulsatile tinnitus can be both induced and suppressed by activation of the somatosensory system of the head or upper lateral neck, we propose that this syndrome is occurring from (a) cardiac synchronous somatosensory activation of the central auditory pathway or (b) failure of the somatosensory-auditory central nervous system interactions to suppress cardiac somatosounds. PMID:18632767

Levine, Robert Aaron; Nam, Eui-Cheol; Melcher, Jennifer

2008-01-01

401

In-depth Proteomics Characterization of Embryogenesis of the Honey Bee Worker (Apis mellifera ligustica).  

PubMed

Identifying proteome changes of honey bee embryogenesis is of prime importance for unraveling the molecular mechanisms that they underlie. However, many proteomic changes during the embryonic period are not well characterized. We analyzed the proteomic alterations over the complete time course of honey bee worker embryogenesis at 24, 48, and 72 h of age, using mass spectrometry-based proteomics, label-free quantitation, and bioinformatics. Of the 1460 proteins identified the embryo of all three ages, the core proteome (proteins shared by the embryos of all three ages, accounting for 40%) was mainly involved in protein synthesis, metabolic energy, development, and molecular transporter, which indicates their centrality in driving embryogenesis. However, embryos at different developmental stages have their own specific proteome and pathway signatures to coordinate and modulate developmental events. The young embryos (<24 h) stronger expression of proteins related to nutrition storage and nucleic acid metabolism may correlate with the cell proliferation occurring at this stage. The middle aged embryos (24-48 h) enhanced expression of proteins associated with cell cycle control, transporters, antioxidant activity, and the cytoskeleton suggest their roles to support rudimentary organogenesis. Among these proteins, the biological pathways of aminoacyl-tRNA biosynthesis, ?-alanine metabolism, and protein export are intensively activated in the embryos of middle age. The old embryos (48-72 h) elevated expression of proteins implicated in fatty acid metabolism and morphogenesis indicate their functionality for the formation and development of organs and dorsal closure, in which the biological pathways of fatty acid metabolism and RNA transport are highly activated. These findings add novel understanding to the molecular details of honey bee embryogenesis, in which the programmed activation of the proteome matches with the physiological transition observed during embryogenesis. The identified biological pathways and key node proteins allow for further functional analysis and genetic manipulation for both the honey bee embryos and other eusocial insects. PMID:24895377

Fang, Yu; Feng, Mao; Han, Bin; Lu, Xiaoshan; Ramadan, Haitham; Li, Jianke

2014-09-01

402

Germ band retraction as a landmark in glucose metabolism during Aedes aegypti embryogenesis  

PubMed Central

Background The mosquito A. aegypti is vector of dengue and other viruses. New methods of vector control are needed and can be achieved by a better understanding of the life cycle of this insect. Embryogenesis is a part of A. aegypty life cycle that is poorly understood. In insects in general and in mosquitoes in particular energetic metabolism is well studied during oogenesis, when the oocyte exhibits fast growth, accumulating carbohydrates, lipids and proteins that will meet the regulatory and metabolic needs of the developing embryo. On the other hand, events related with energetic metabolism during A. aegypti embryogenesis are unknown. Results Glucose metabolism was investigated throughout Aedes aegypti (Diptera) embryonic development. Both cellular blastoderm formation (CBf, 5 h after egg laying - HAE) and germ band retraction (GBr, 24 HAE) may be considered landmarks regarding glucose 6-phosphate (G6P) destination. We observed high levels of glucose 6-phosphate dehydrogenase (G6PDH) activity at the very beginning of embryogenesis, which nevertheless decreased up to 5 HAE. This activity is correlated with the need for nucleotide precursors generated by the pentose phosphate pathway (PPP), of which G6PDH is the key enzyme. We suggest the synchronism of egg metabolism with carbohydrate distribution based on the decreasing levels of phosphoenolpyruvate carboxykinase (PEPCK) activity and on the elevation observed in protein content up to 24 HAE. Concomitantly, increasing levels of hexokinase (HK) and pyruvate kinase (PK) activity were observed, and PEPCK reached a peak around 48 HAE. Glycogen synthase kinase (GSK3) activity was also monitored and shown to be inversely correlated with glycogen distribution during embryogenesis. Conclusions The results herein support the hypothesis that glucose metabolic fate changes according to developmental embryonic stages. Germ band retraction is a moment that was characterized as a landmark in glucose metabolism during Aedes aegypti embryogenesis. Furthermore, the results also suggest a role for GSK3 in glycogen balance/distribution during morphological modifications. PMID:20184739

2010-01-01

403

Somatic HIF2A gain-of-function mutations in paraganglioma with polycythemia.  

PubMed

Hypoxia-inducible factors are transcription factors controlling energy, iron metabolism, erythropoiesis, and development. When these proteins are dysregulated, they contribute to tumorigenesis and cancer progression. However, mutations in genes encoding ? subunits of hypoxia-inducible factors (HIF-?) have not previously been identified in any cancer. Here we report two novel somatic gain-of-function mutations in the gene encoding hypoxia-inducible factor 2? (HIF2A) in two patients, one presenting with paraganglioma and the other with paraganglioma and somatostatinoma, both of whom had polycythemia. The two mutations were associated with increased HIF-2? activity and increased protein half-life. PMID:22931260

Zhuang, Zhengping; Yang, Chunzhang; Lorenzo, Felipe; Merino, Maria; Fojo, Tito; Kebebew, Electron; Popovic, Vera; Stratakis, Constantine A; Prchal, Josef T; Pacak, Karel

2012-09-01

404

Processive AID-catalysed cytosine deamination on single-stranded DNA simulates somatic hypermutation  

Microsoft Academic Search

Activation-induced cytidine deaminase (AID) is a protein required for B cells to undergo class switch recombination and somatic hypermutation (SHM)-two processes essential for producing high-affinity antibodies. Purified AID catalyses the deamination of C to U on single-stranded (ss)DNA. Here, we show in vitro that AID-catalysed C deaminations occur preferentially on 5' WRC sequences in accord with SHM spectra observed in

Phuong Pham; Ronda Bransteitter; John Petruska; Myron F. Goodman

2003-01-01

405

Somatic hybrids of vegetable brassicas as source for new resistances to fungal and virus diseases  

Microsoft Academic Search

Somatic hybrids were produced by PEG-induced symmetric and asymmetric protoplast fusions in order to transfer resistance to\\u000a Alternaria brassicicola, A. brassicae, Phoma\\u000a lingam, Plasmodiophora brassicae and Turnip mosaic virus (TuMV) into Brassica oleracea var. capitata (cv. ‘Toskama’) and botrytis (cv. ‘Korso’). As resistance donors, ten species belonging to several genera of the family Brassicaceae including wild relatives\\u000a were used. Of

Paul Scholze; Reiner Krämer; Ulrich Ryschka; Evelyn Klocke; Günter Schumann

2010-01-01

406

Formulation of Nutrient Medium for In Vitro Somatic Embryo Induction in Plantago ovata Forsk  

Microsoft Academic Search

A nutrient medium has been formulated by altering the macro- and micro-elemental concentration in the culture medium for in\\u000a vitro somatic embryo induction of economically important medicinal plant Plantago ovata Forsk .A comparison was made between induced embryos with normal embryos (produced in Murashige and Skoog (MS) medium) to\\u000a observe frequency of embryo induction and also to determine regeneration efficiency.

Priyanka Saha; Subhendu Bandyopadhyay; Sarmistha Sen Raychaudhuri

2011-01-01

407

The Absence of p53 Promotes Metastasis in a Novel Somatic Mouse Model for Hepatocellular Carcinoma  

Microsoft Academic Search

We have generated a mouse model for hepatocellular carcinoma using somatic delivery of oncogene-bearing avian retroviral vectors to the liver cells of mice expressing the viral receptor TVA under the control of the albumin gene promoter (Alb-TVA mice). Viruses encoding mouse polyoma virus middle T antigen (PyMT) induced tumors, which can be visualized with magnetic resonance imaging, in 65% of

Brian C. Lewis; David S. Klimstra; Nicholas D. Socci; Su Xu; Jason A. Koutcher; Harold E. Varmus

2005-01-01

408

Clathrin Heavy Chain Is Important for Viability, Oviposition, Embryogenesis and, Possibly, Systemic RNAi Response in the Predatory Mite Metaseiulus occidentalis  

PubMed Central

Clathrin heavy chain has been shown to be important for viability, embryogenesis, and RNA interference (RNAi) in arthropods such as Drosophila melanogaster. However, the functional roles of clathrin heavy chain in chelicerate arthropods, such as the predatory mite Metaseiulus occidentalis, remain unknown. We previously showed that dsRNA ingestion, followed by feeding on spider mites, induced systemic and robust RNAi in M. occidentalis females. In the current study, we performed a loss-of-function analysis of the clathrin heavy chain gene in M. occidentalis using RNAi. We showed that ingestion of clathrin heavy chain dsRNA by M. occidentalis females resulted in gene knockdown and reduced longevity. In addition, clathrin heavy chain dsRNA treatment almost completely abolished oviposition by M. occidentalis females and the few eggs produced did not hatch. Finally, we demonstrated that clathrin heavy chain gene knockdown in M. occidentalis females significantly reduced a subsequent RNAi response induced by ingestion of cathepsin L dsRNA. The last finding suggests that clathrin heavy chain may be involved in systemic RNAi responses mediated by orally delivered dsRNAs in M. occidentalis. PMID:25329675

Wu, Ke; Hoy, Marjorie A.

2014-01-01

409

Human oocytes reprogram adult somatic nuclei of a type 1 diabetic to diploid pluripotent stem cells.  

PubMed

The transfer of somatic cell nuclei into oocytes can give rise to pluripotent stem cells that are consistently equivalent to embryonic stem cells, holding promise for autologous cell replacement therapy. Although methods to induce pluripotent stem cells from somatic cells by transcription factors are widely used in basic research, numerous differences between induced pluripotent stem cells and embryonic stem cells have been reported, potentially affecting their clinical use. Because of the therapeutic potential of diploid embryonic stem-cell lines derived from adult cells of diseased human subjects, we have systematically investigated the parameters affecting efficiency of blastocyst development and stem-cell derivation. Here we show that improvements to the oocyte activation protocol, including the use of both kinase and translation inhibitors, and cell culture in the presence of histone deacetylase inhibitors, promote development to the blastocyst stage. Developmental efficiency varied between oocyte donors, and was inversely related to the number of days of hormonal stimulation required for oocyte maturation, whereas the daily dose of gonadotropin or the total number of metaphase II oocytes retrieved did not affect developmental outcome. Because the use of concentrated Sendai virus for cell fusion induced an increase in intracellular calcium concentration, causing premature oocyte activation, we used diluted Sendai virus in calcium-free medium. Using this modified nuclear transfer protocol, we derived diploid pluripotent stem-cell lines from somatic cells of a newborn and, for the first time, an adult, a female with type 1 diabetes. PMID:24776804

Yamada, Mitsutoshi; Johannesson, Bjarki; Sagi, Ido; Burnett, Lisa Cole; Kort, Daniel H; Prosser, Robert W; Paull, Daniel; Nestor, Michael W; Freeby, Matthew; Greenberg, Ellen; Goland, Robin S; Leibel, Rudolph L; Solomon, Susan L; Benvenisty, Nissim; Sauer, Mark V; Egli, Dieter

2014-06-26

410

Differences in gene expression patterns between somatic cell nuclear transfer embryos constructed with either rabbit granulosa cells or their derivatives  

Microsoft Academic Search

Successful production of offspring by somatic cell nuclear transfer (SCNT) is affected by the nature of the donor cells used. The purpose of this study was to determine whether characteristic changes induced in donor cells by culture conditions influenced gene expression patterns in the resultant SCNT embryos. Rabbit granulosa cells (rGC) were cultured under different conditions, either with or without

Fukashi Inoue; Junichi Matsuda; Katsuhiro Ohkoshi; Tadashi Furusawa; Seiya Takahashi; Hiroshi Sasada; Eimei Sato; Tomoyuki Tokunaga

2006-01-01

411

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

412

Family background and sexual abuse associated with somatization.  

PubMed

To help clarify the complex association between negative childhood experiences and somatization, the authors examined the possible relationship between self-reported childhood sexual abuse, dysfunctional family background and several types of somatization in a nonclinical sample. Three anonymous questionnaires were completed by 202 female university students (average age 22 years). The findings confirm that severe or repeated childhood sexual victimization and a familial deficiency syndrome in childhood may be important in the pathogenesis of somatization. PMID:8559957

Kinzl, J F; Traweger, C; Biebl, W

1995-01-01

413

piggyBac Transposon Somatic Mutagenesis with an Activated Reporter and Tracker (PB-SMART) for Genetic Screens in Mice  

PubMed Central

Somatic forward genetic screens have the power to interrogate thousands of genes in a single animal. Retroviral and transposon mutagenesis systems in mice have been designed and deployed in somatic tissues for surveying hematopoietic and solid tumor formation. In the context of cancer, the ability to visually mark mutant cells would present tremendous advantages for identifying tumor formation, monitoring tumor growth over time, and tracking tumor infiltrations and metastases into wild-type tissues. Furthermore, locating mutant clones is a prerequisite for screening and analyzing most other somatic phenotypes. For this purpose, we developed a system using the piggyBac (PB) transposon for somatic mutagenesis with an activated reporter and tracker, called PB-SMART. The PB-SMART mouse genetic screening system can simultaneously induce somatic mutations and mark mutated cells using bioluminescence or fluorescence. The marking of mutant cells enable analyses that are not possible with current somatic mutagenesis systems, such as tracking cell proliferation and tumor growth, detecting tumor cell infiltrations, and reporting tissue mutagenesis levels by a simple ex vivo visual readout. We demonstrate that PB-SMART is highly mutagenic, capable of tumor induction with low copy transposons, which facilitates the mapping and identification of causative insertions. We further integrated a conditional transposase with the PB-SMART system, permitting tissue-specific mutagenesis with a single cross to any available Cre line. Targeting the germline, the system could also be used to conduct F1 screens. With these features, PB-SMART provides an integrated platform for individual investigators to harness the power of somatic mutagenesis and phenotypic screens to decipher the genetic basis of mammalian biology and disease. PMID:22039523

Bosenberg, Marcus W.; Xu, Tian

2011-01-01

414

Knockout of exogenous EGFP gene in porcine somatic cells using zinc-finger nucleases  

SciTech Connect

Research highlights: {yields} EGFP gene integrated in porcine somatic cells could be knocked out using the ZFN-KO system. {yields} ZFNs induced targeted mutations in porcine primary cultured cells. {yields} Complete absence of EGFP fluorescence was confirmed in ZFN-treated cells. -- Abstract: Zinc-finger nucleases (ZFNs) are expected as a powerful tool for generating gene knockouts in laboratory and domestic animals. Currently, it is unclear whether this technology can be utilized for knocking-out genes in pigs. Here, we investigated whether knockout (KO) events in which ZFNs recognize and cleave a target sequence occur in porcine primary cultured somatic cells that harbor the exogenous enhanced green fluorescent protein (EGFP) gene. ZFN-encoding mRNA designed to target the EGFP gene was introduced by electroporation into the cell. Using the Surveyor nuclease assay and flow cytometric analysis, we confirmed ZFN-induced cleavage of the target sequence and the disappearance of EGFP fluorescence expression in ZFN-treated cells. In addition, sequence analysis revealed that ZFN-induced mutations such as base substitution, deletion, or insertion were generated in the ZFN cleavage site of EGFP-expression negative cells that were cloned from ZFN-treated cells, thereby showing it was possible to disrupt (i.e., knock out) the function of the EGFP gene in porcine somatic cells. To our knowledge, this study provides the first evidence that the ZFN-KO system can be applied to pigs. These findings may open a new avenue to the creation of gene KO pigs using ZFN-treated cells and somatic cell nuclear transfer.

Watanabe, Masahito [Japan Science and Technology Agency (JST), ERATO, Nakauchi Stem Cell and Organ Regeneration Project, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan) [Japan Science and Technology Agency (JST), ERATO, Nakauchi Stem Cell and Organ Regeneration Project, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Umeyama, Kazuhiro [Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan) [Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); International Cluster for Bio-Resource Research, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Matsunari, Hitomi [Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan)] [Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Takayanagi, Shuko [Japan Science and Technology Agency (JST), ERATO, Nakauchi Stem Cell and Organ Regeneration Project, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan) [Japan Science and Technology Agency (JST), ERATO, Nakauchi Stem Cell and Organ Regeneration Project, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Haruyama, Erika; Nakano, Kazuaki; Fujiwara, Tsukasa; Ikezawa, Yuka [Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan)] [Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Nakauchi, Hiromitsu [Japan Science and Technology Agency (JST), ERATO, Nakauchi Stem Cell and Organ Regeneration Project, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan) [Japan Science and Technology Agency (JST), ERATO, Nakauchi Stem Cell and Organ Regeneration Project, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Center for Stem Cell Biology and Regenerative Medicine, Institute of Medical Science, Tokyo University, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); and others

2010-11-05

415

A SOMATIC-MARKER THEORY OF ADDICTION  

PubMed Central

Similar to patients with ventromedial prefrontal cortex (VMPC) lesions, substance abusers show altered decision-making, characterized by a tendency to choose the immediate reward, at the expense of negative future consequences. The somatic-marker model proposes that decision-making depends on neural substrates that regulate homeostasis, emotion and feeling. According to this model, there should be a link between alterations in processing emotions in substance abusers, and their impairments in decision-making. A growing evidence from neuroscientific studies indicate that core aspects of addiction may be explained in terms of abnormal emotional/homeostatic guidance of decision-making. Behavioural studies have revealed emotional processing and decision-making deficits in substance abusers. Neuroimaging studies have shown that altered decision-making in addiction is associated with abnormal functioning of a distributed neural network critical for the processing of emotional information, and the experience of “craving”, including the VMPC, the amygdala, the striatum, the anterior cingulate cortex, and the insular/somato-sensory cortices, as well as non-specific neurotransmitter systems that modulate activities of neural processes involved in decision-making. The aim of this paper is to review this growing evidence, and to examine the extent of which these studies support a somatic-marker theory of addiction. We conclude that there are at least two underlying types of dysfunctions where emotional signals (somatic-markers) turns in favor of immediate outcomes in addiction: (1) a hyperactivity in the amygdala or impulsive system, which exaggerates the rewarding impact of available incentives, and (2) hypoactivity in the prefrontal cortex or reflective system, which forecasts the long-term consequences of a given action. PMID:18722390

Verdejo-Garcia, Antonio; Bechara, Antoine

2009-01-01

416

Somatic sensory cortex of llama (Lama glama).  

PubMed

The somatic sensory cortex (SI and SII) was mapped in llamas using microelectrode mapping methods developed earlier in a study of SI of the slow loris. Projections to SI from the llama's prehensile browsing lips were differentially enlarged when compared to those reported for sheep. In llama, SII was reversed in its mediolatreal pattern from that reported for SII in most other mammals. Fissural landmarks reliably demarcated different projections within SI, between SI and SII and between SI or SII and other surrounding nonsensory areas. The use of microelectrode mapping methods in different mammals to determine gyral and fissural homologies is discussed. PMID:990910

Welker, W I; Adrian, H O; Lifshitz, W; Kaulen, R; Caviedes, E; Gutman, W

1976-01-01

417

A Digital Framework to Build, Visualize and Analyze a Gene Expression Atlas with Cellular Resolution in Zebrafish Early Embryogenesis  

E-print Network

A gene expression atlas is an essential resource to quantify and understand the multiscale processes of embryogenesis in time and space. The automated reconstruction of a prototypic 4D atlas for vertebrate early embryos, ...

Luengo-Oroz, Miguel A.

418

Thermal manipulation during embryogenesis has long-term effects on muscle and liver metabolism in fast-growing chickens.  

PubMed

Fast-growing chickens have a limited ability to tolerate high temperatures. Thermal manipulation during embryogenesis (TM) has previously been shown to lower chicken body temperature (Tb) at hatching and to improve thermotolerance until market age, possibly resulting from changes in metabolic regulation. The aim of this study was to evaluate the long-term effects of TM (12 h/d, 39.5°C, 65% RH from d 7 to 16 of embryogenesis vs. 37.8°C, 56% RH continuously) and of a subsequent heat challenge (32°C for 5 h at 34 d) on the mRNA expression of metabolic genes and cell signaling in the Pectoralis major muscle and the liver. Gene expression was analyzed by RT-qPCR in 8 chickens per treatment, characterized by low Tb in the TM groups and high Tb in the control groups. Data were analyzed using the general linear model of SAS consid