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1

Influence of the stage for anther excision and heterostyly in embryogenesis induction from eggplant anther cultures  

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In this work we address two aspects of eggplant flower biology potentially involved on the efficiency of anther culture: the selection of the best floral stage to extract anthers for culture, and the effect of heterostyly in the identification of suitable buds and anthers. For 12 different accessions, we determined morphological criteria (length ranges) to identify buds and anthers enriched in vacuolate microspores and young bicellular pollen, the stages most responsive to embryogenesis induc...

Rivas Sendra, Alba; Prohens Toma?s, Jaime; Segui?-simarro, Jose? M.; Salas Aragon, Pablo

2012-01-01

2

Evaluation of gelling agents on anther culture: response of two soybean cultivars  

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Anthers of two soybean cultivars were cultured in B5 long basal culture media gelled with agarose or PhytagelTM. Cytological examinations of the anthers were carried out during the first 45 days of culture to assay the viability and developmental stage of microspores. Frequency of callus formation was recorded at 45 days of culture. The analysis of variance of the microspore viability assay showed significant Cultivar X Gelling Agent X Day of Culture interactions. The frequencies of viable mi...

Milena Barcelos Cardoso; Maria Helena Bodanese-Zanettini; Elsa Cristina de Mundstock; Eliane Kaltchuk-Santos

2007-01-01

3

Response of anther culture in vitro to irradiation of spike and culturing with Al stress in barley  

International Nuclear Information System (INIS)

Spikes of two barley lines treated with 60Co ?-radiation as anther culture materials, the callus induction and green plant regeneration were investigated on the media containing Al. The results showed that the frequency of callus induction was dramatically decreased by irradiation treatment and green plant regeneration was failed at a dose of 10 Gy. The calli was obtained from anthers cultured with Al-medium, and also green plants were regenerated even in higher Al concentration. The frequency of callus induction was reduced in culturing with higher stress of Al, and the green plant regeneration was also decreased. (authors)

2005-02-01

4

Response of different genotypes of wheat, rice and black beans to anther, embryo and other tissue cultures  

International Nuclear Information System (INIS)

The objective of the basic studies we have been conducting in our laboratory is to establish callus induction and in vitro plant regeneration protocols starting with several tissues of Guatemalan varieties of wheat (Triticum aesticum L.), rice (Oryza sativa L.) and especially black bean (Phaseolus vulgaris L.) in order to obtain disease resistance, earliness, and dwarf plants. Wheat anthers and immature embryos of varieties Patzun, Comalapa, Chocoyo, and Xequijel cultured in N6, Potato II, and MS basal media supplemented with auxin and cytokinin gave the best responses in callus induction and plant regeneration. Anthers and mature embryos of indica rice varieties Precozicta and Virginai, when cultured in MS, B5, N6, and Potato II basal media with different hormonal combinations gave a good response in callus induction. However, a satisfactory response in plant regeneration was not obtained. With black beans, when hypocotyls and mature embryos of black bean varieties Quinack Che and Parramos were cultured in MS basal medium supplemented with different concentrations of NAA and kinetin, more than 60% callus induction was produced. When Quinack Che calli were transferred to MS basal medium supplemented with 1 mg/l NAA plus 0.5 mg/l BAP, green points of regeneration were visible in these calli. (author). 34 refs, 28 tabs

1996-01-01

5

Study of genotype, cold pre-treatment, low-dosage Gamma irradiation and 2,4-D concentration effects on wheat anther culture response  

International Nuclear Information System (INIS)

In this study. effects of genotype, cold pre-treatment. low dosage Gamma irradiation and 2, 4-D concentration on response of three wheat genotypes (Atrak, F3 2005 and F3 2104) to anther culture were investigated. Seeds of donor genotypes were grown under field condition in early spring. Anthers from donor plants were collected and plated on modified CHB medium containing 2,4-D (2 and 4 mgl-1), 0.5 mgl-1 Kinetin and gl-1 Sucrose. Number of calli formed in 100 anthers and number of planet produced from 100 calli were counted. Results indicated that genotypes. cold pre-treatments and 2,4-D concentrations had significant effects on response of wheat genotypes to anther production, while F3 2104 the lowest. It would be concluded that androgenic traits are controlled by genotype and environmental factors. Furthermore this traits are controlled independently

2005-01-01

6

Evaluation of gelling agents on anther culture: response of two soybean cultivars  

Directory of Open Access Journals (Sweden)

Full Text Available Anthers of two soybean cultivars were cultured in B5 long basal culture media gelled with agarose or PhytagelTM. Cytological examinations of the anthers were carried out during the first 45 days of culture to assay the viability and developmental stage of microspores. Frequency of callus formation was recorded at 45 days of culture. The analysis of variance of the microspore viability assay showed significant Cultivar X Gelling Agent X Day of Culture interactions. The frequencies of viable microspores decreased significantly with time of culture, within each cultivar and gelling agent tested. The interaction Day X Cultivar was significant for the frequencies of binucleate symmetrical grains and multinucleate/multicellular structures. The effect of gelling agents on the frequency of binucleate symmetrical pollens grains and multinucleate/multicellular structures was not significant. About the frequencies of calli and embryogenic calli formed, a significant difference was detected between the cultivars (IAS5= 14.8% and BRS 133=6.6%. Gelling agents showed no effect over these frequencies.Anteras de duas cultivares de soja foram cultivadas em meio de cultura basal B5 longo gelificado com agarose ou Phytagel®. Análises citológicas das anteras foram conduzidas durante os primeiros 45 dias de cultura para avaliar a viabilidade e o estágio de desenvolvimento dos micrósporos. A freqüência de formação de calos foi analisada após 45 dias do início da cultura. A análise da variância da viabilidade do micrósporo mostrou interações significativas de Cultivar X Agente Gelificante X Dias de Cultura. As freqüências de grãos de pólen viáveis diminuíram significativamente com o tempo de cultura, dentro de cada cultivar e agente gelificante testado. A interação Dia X Cultivar foi significante para as freqüências de grãos de pólen binucleados simétricos e estruturas multinucleados/multicelulares. O efeito do agente gelificante na freqüência de grãos de pólen binucleados simétricos e estruturas multinucleados/multicelulares não foi significante. Com relação às freqüências de calos e estruturas embriogênicas formadas, houve diferença significativa entre cultivares (IAS5= 14.8% e BRS 133=6.6%. O agente gelificante não mostrou efeito em tais freqüências.

Milena Barcelos Cardoso

2007-11-01

7

Evaluation of gelling agents on anther culture: response of two soybean cultivars  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Anteras de duas cultivares de soja foram cultivadas em meio de cultura basal B5 longo gelificado com agarose ou Phytagel®. Análises citológicas das anteras foram conduzidas durante os primeiros 45 dias de cultura para avaliar a viabilidade e o estágio de desenvolvimento dos micrósporos. A freqüência [...] de formação de calos foi analisada após 45 dias do início da cultura. A análise da variância da viabilidade do micrósporo mostrou interações significativas de Cultivar X Agente Gelificante X Dias de Cultura. As freqüências de grãos de pólen viáveis diminuíram significativamente com o tempo de cultura, dentro de cada cultivar e agente gelificante testado. A interação Dia X Cultivar foi significante para as freqüências de grãos de pólen binucleados simétricos e estruturas multinucleados/multicelulares. O efeito do agente gelificante na freqüência de grãos de pólen binucleados simétricos e estruturas multinucleados/multicelulares não foi significante. Com relação às freqüências de calos e estruturas embriogênicas formadas, houve diferença significativa entre cultivares (IAS5= 14.8% e BRS 133=6.6%). O agente gelificante não mostrou efeito em tais freqüências. Abstract in english Anthers of two soybean cultivars were cultured in B5 long basal culture media gelled with agarose or PhytagelTM. Cytological examinations of the anthers were carried out during the first 45 days of culture to assay the viability and developmental stage of microspores. Frequency of callus formation w [...] as recorded at 45 days of culture. The analysis of variance of the microspore viability assay showed significant Cultivar X Gelling Agent X Day of Culture interactions. The frequencies of viable microspores decreased significantly with time of culture, within each cultivar and gelling agent tested. The interaction Day X Cultivar was significant for the frequencies of binucleate symmetrical grains and multinucleate/multicellular structures. The effect of gelling agents on the frequency of binucleate symmetrical pollens grains and multinucleate/multicellular structures was not significant. About the frequencies of calli and embryogenic calli formed, a significant difference was detected between the cultivars (IAS5= 14.8% and BRS 133=6.6%). Gelling agents showed no effect over these frequencies.

Milena Barcelos, Cardoso; Maria Helena, Bodanese-Zanettini; Elsa Cristina de, Mundstock; Eliane, Kaltchuk-Santos.

8

Variation for improved protein and yield from rice anther culture.  

Science.gov (United States)

The anther culture technique is useful for the recovery of haploids which when doubled provide homozygosity. Additionally, beneficial as well as deleterious genetic and epigenetic changes are promoted by the in vitro procedures. The majority of plants recovered from anther calli of the cultivar 'Calrose 76' were similar to the starting cultivar but plants regenerated from microspore calli had a wider range of responses than controls for several characteristics. Plants with larger seeds, higher levels of seed protein, shorter stature and more highly tillered than the starting cultivar were obtained from selfed anther-derived plants. The data also support the concept that in vitro procedures including anther culture of specific cultivars of rice promoted the recovery of phenotypes with increased seed storage proteins. PMID:24258756

Schaeffer, G W; Sharpe, F T; Cregan, P B

1984-03-01

9

Anther culture of chili pepper (Capsicum spp.).  

Science.gov (United States)

Chili pepper (Capsicum spp.) is a very important horticultural crop around the world and is especially important for Mexicans because of its impact in the culture and the cuisine. Biotechnological tools such as tissue culture techniques and specifically anther culture may be applied successfully for plant breeding and genetic improvement in order to generate isogenic lines (100% homozygous) in a shorter time in comparison with the classic breeding methods. In this chapter, a protocol for efficient recovery of chili pepper haploid plants from in vitro cultured anthers is described. PMID:22610631

Ochoa-Alejo, Neftalí

2012-01-01

10

Attempts to induce haploids in anther cultures of sugar, fodder and wild species of beet  

Directory of Open Access Journals (Sweden)

Full Text Available In the present investigation, aimed at obtaining beet haploids from anthers, the effect of mineral media, potato and sugar beet extract and p-fluorophenylalanine (PFP in combination with growth substances was tested. Nutrient-starved plants as anther-donors, anther-starvation, cold treatment and photoperiod were also analysed. On all mineral media the anthers produced callus and roots; however, the percentage depended on the combination of growth substances used. The best medium for differentiation was that of Linsmaier and Skoog with 25 µM zeatin or 6-(3-methyl-2-butenylaminopurine with 5 µM naphthalene-l-acetic acid (25.5%. The addition of PFP caused an increase in the percentage of anther differentiation (41.6%. Besides callus and roots on one of the anthers (in ca. 140000 tested, vegetative buds were formed from which numerous plants were obtained (2n. Plant and anther nutrient starvation did not improve the anther response to differentiation, nor did it induce haploid development, similarly as cold treatment of inflorescences or isolated anthers. The anthers of wild species showed lower ability to differentiate than those of sugar or fodder beets. Cytological analyses showed formation of multicellular structures until ca. the 12-th day of anther culture; afterwards, they degenerated.

Janina Rogozi?ska

1982-03-01

11

Effect of spikelet position on rice anther culture efficiency.  

Science.gov (United States)

The potential of anthers from different parts of the panicle to induce callus was investigated with the japonica rice variety Taipei 309. The results showed that the callusing abilities of anthers from different spikelet positions were significantly different. After plating 4483, 4496, 4348 anthers from the basal, middle and top parts, the percentage of anthers forming calli was 20% in the basal part, 12% in the middle part and 8% in the top part. The anthers of basal parts containing pollen at all uninucleate stages, including early, middle and late, showed higher callus induction frequency than those from middle and top parts. The green plantlet regeneration frequencies of top, middle and basal spikelets were around 18% in all three cases. From the results it would appear that anthers from the basal part of the panicle should be used in anther culture of rice in order to obtain higher efficiencies, and thereby optimise the usefulness of this technique in rice breeding programmes. PMID:10717321

Afza; Shen; Zapata-Arias; Xie; Fundi; Lee; Bobadilla-Mucino; Kodym

2000-04-25

12

Induction of haploid morphogenic calluses from in vitro cultured anthers  

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Apricot (Prunus armeniaca) ‘Harcot’ anthers were cultured in vitro for the production of haploid plants. The best androgenic response was achieved with Nitsch and Nitsch (1969) medium, supplemented with 4.52 microM 2,4-D, 4.52 micoM zeatin, 2.85 microM IAA and 40 g l?1 sucrose. Cultures were maintained in the dark for 8 days, at 28 ?C, followed by transfer to a 16-h photoperiod, with 35 micro mm?2 s?1 light intensity and 24/22 ?C day/night temperature. The androgenic response wa...

Peixe, Augusto; Barroso, Joa?o; Potes, Amely; Pais, Maria

2004-01-01

13

Induction of Haploid Rice Plants Through in vitro Anther Culture  

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Full Text Available Anthers of three rice cultivars having late uninucleate microspores were studied for induction of haploid rice plants. Anthers were cultured on Z2 medium supplemented with various combinations and concentrations of auxins and kinetin (cytokinin. The best callusing from cultured anthers obtained in 2 medium containing 2,4-D 2 mg l-1, NAA 2.5 mg l-1 and kin 0.5 mg l-1. For regeneration of haploid plantlets anther derived calli were transferred to modified MS medium enriched with kin 1 mg l-1, NAA 1 mg l-1, BAP 1.0 ml l-1 and incubated at 25?1OC in light. BRRI Dhan-29 produced both green and albino plants while BR-3 produced green plants only. Green plantlets obtained from BRRI Dhan-29 were examined and found to be 69.2% haploid plants.

Sharmin Shahnewaz

2003-01-01

14

Effect of the genotype and gamma irradiation on the anther cultures of a 10x10 diallel cross of wheat  

International Nuclear Information System (INIS)

Anther culture responsiveness, irradiation effect and reciprocal effect were evaluated on ten genotypes (V1-V10) and a 101x0 diallel cross. Gamma irradiation dose of 100 Gy was applied to seeds of parents and F1 cross from which the donor plants were grown. Non-irradiated donor plants were also used for comparison. Anthers were plated on potato-2 callus induction medium and calli formed were transferred to MS medium supplemented with sucrose (3%), indolacetic acid (1.0 mg/L), kinetin (1.0 mg/L), inositol (100 mg/L) and solidified with agar (0.7%). Genotypes showed big differences for callus induction, plant regeneration and anther culturability rate. The most responsive materials were V2, V10 and V5 with 76.0, 27.4 and 10.8 green plants per 100 anthers respectively. No irradiation effect was found for the parents nor the F1 crosses on the pooled data. Mean anther culture response of specific genotypes showed that irradiation significantly increased anther culturability rate of V3 from 0.1 to 27.6 green plants per 100 anthers. No reciprocal effect was observed. (author)

2001-05-01

15

Androgenesis in anther culture of Lithuanian spring barley cultivars  

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The method of anther culture was used for the production of doubled haploids in Lithuanian spring barley cultivars. Two methods, (i) regeneration from callus (Szarjeko’s method) and (ii) direct regeneration from embryoids (Caredda’s method) were applied to determine the androgenic potential according to the green regenerant yield and other morphogenetic factors. Green double haploid regenerants were obtained in four Lithuanian spring barley cultivars (‘Aura’, ‘Aidas’, ‘Alsa’ a...

Asakavic?iu?te?, R.; Pas?akinskiene?, I.

2006-01-01

16

Improvement of bananas (Musa cvs.) through in vitro anther culture  

International Nuclear Information System (INIS)

Agricultural products play a great role in the Colombian economy, and the banana is one of the most important. Since 1981, one of the more serious problems effecting production of this crop is the fungus Mycosphaerella fijensis sp. difformis, that causes black sigatoka disease. Most of the recent efforts to control this disease have been directed towards the identification of clones tolerant or resistant to this disease. One alternative approach is the use of anther culture to obtain resistant haploid plants. Diploid clones (Musa - AA) have been used as a model in this study. The results presented here identify the most appropriate stage of anther development for callus induction and proliferation, and treatments that reduce tissue browning. (author). 12 refs, 1 fig., 1 tab

1995-06-01

17

High production of wheat double haploids via anther culture  

Directory of Open Access Journals (Sweden)

Full Text Available Androgenous and regeneration abilities of 14 randomly selected F1 hybrids of wheat (Triticum aestivum L. were analyzed. Anthers were grown in vitro on a modified Potato-2 inductive medium. The hybrid NS111-95/Ana had the highest average values for androgenous capacity (33% and callus yield (119%, while the hybrid NS 92-250/Tiha had the lowest values for these traits (9 and 21%, respectively. Seven genotypes (50% had a frequency of green plants relative to the number of isolated anthers of over 10%, with the highest frequency of 21.3% (NS111-95/Sremica. This hybrid produced 12.8 doubled haploid (DH lines per spike used for isolation. In the other genotypes, the number of produced DH lines per spike ranged from 1 (30­Sc.Smoc.88-89/Hays-2 to 11.2 (NS111-95/Ana. As half of the randomly selected genotypes exhibited high green plant regeneration ability and a high production of DH lines per spike, it can be concluded that in vitro anther culture can be successfully used in breeding programs for rapid production of homozygous wheat lines.

Kondi?-Šipka Ankica

2007-01-01

18

Evaluation of androgenic competence through anther culture in common eggplant and related species  

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Anther culture is a convenient technique to obtain androgenic haploid and doubled haploid (DH) plants. In common eggplant (Solanum melongena), this technique has been used to develop DH pure lines for producing uniform F1 hybrid seed of some commercial varieties. However, a comprehensive study of the variation of this useful trait among different materials of common eggplant and related species is still lacking. In this work, we studied the androgenic response of 12 accessions of common eggpl...

Pablo; Prohens Toma?s, Jaime; Segui?-simarro, Jose? M.; Salas Aragon, Pablo

2011-01-01

19

Adapting rice anther culture to gene transformation and RNA interference.  

Science.gov (United States)

Anther culture offers a rapid method of generating homozygous lines for breeding program and genetic analysis. To produce homozygous transgenic lines of rice (Oryza sativa L.) in one step, we developed an efficient protocol of anther-callus-based transformation mediated by Agrobacterium after optimizing several factors influencing efficient transformation, including callus induction and Agrobacterium density for co-cultivation. Using this protocol, we obtained 145 independent green transformants from five cultivars of japonica rice by transformation with a binary vector pCXK1301 bearing the rice gene, Xa21 for resistance to bacterial blight, of which 140 were further confirmed by PCR and Southern hybridization analysis, including haploids (32.1%), diploids (62.1%) and mixoploids (7.5%). Fifteen diploids were found to be doubled haploids, which accounted for 10.7% of the total positive lines. Finally, by including 28 from colchicine induced or spontaneous diploidization of haploids later after transformation, a total of 43 doubled haploids (30.7%) of Xa21 transgenic lines were obtained. We also generated two RNAi transgenic haploids of the rice OsMADS2 gene, a putative redundant gene of OsMADS4 based on their sequence similarity, to investigate its possible roles in rice flower development by this method. Flowers from the two OsMADS2 RNAi transgenic haploids displayed obvious homeotic alternations, in which lodicules were transformed into palea/lemma-like tissues, whereas identities of other floral organs were maintained. The phenotypic alternations were proved to result from specific transcriptional suppression of OsMADS2 gene by the introduced RNAi transgene. The results confirmed that OsMADS2 is involved in lodicule development of rice flower and functionally redundant with OsMADS4 gene. Our results demonstrated that rice anther culture could be adapted to gene transformation and RNAi analysis in rice. PMID:17172048

Chen, Caiyan; Xiao, Han; Zhang, Wenli; Wang, Aiju; Xia, Zhihui; Li, Xiaobing; Zhai, Wenxue; Cheng, Zhukuan; Zhu, Lihuang

2006-10-01

20

Cucumber mosaic virus resistant mutant from tobacco's anthers treated with ? ray through anther culture  

International Nuclear Information System (INIS)

Flower buds of Nicotiana tabacum cv. K326, NC89 and 8611, in which the microspore is in the phase of single nucleus and the nucleus is on the side, were irradiated with 60Co ?-ray. Plant lets from anther culture were transplanted and inoculated with poisonous fluid of CMV. The results showed that there was an orientation relation between the variation of disease resistance of plants of NC89, 8611 and the dose of 60Co ?-ray. The variation of leaves of plants was analogous to symptom of CMV when the dose was equal to or more than 4, which caused difficulty for selection. When dose was less than 2krad, there was no difference in disease resistance between the plants induced from irradiation of 60Co ?-ray and the control. However, when dose was equal to 2krad, the difference of disease resistance was at the level of significance. CMV-resistant mutants were selected from the population of haploid plant of NC89 and 8611 induced by 2.0 krad of 60Co ? ray

1999-04-01

 
 
 
 
21

Evidence for cytoplasmic control of in vitro microspore embryogenesis in the anther culture of wheat (Triticum aestivum L.).  

Science.gov (United States)

Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, 'Siete Cerros 66' and 'Penjamo 62', as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of 'Penjamo 62' in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed. PMID:24226021

Sági, L; Barnabás, B

1989-12-01

22

Mutant in tobacco anther culture induced by 60Co ?-rays  

International Nuclear Information System (INIS)

The tobacco anthers at uninucleate eccentric stage were irradiated by 60Co ?-rays for the purpose of inducing desirable mutants. The results showed that the induction frequency of plantlets increased following 1kR of 60Co ?-rays treatment. However, the time of plantlet induction was delayed and the percentage of responding anthers as well as the number of plantlets induced per anther significantly decreased after 3kR of 60Co ?-ray radiation which was considered as a semilethal exposure. The plantlet numbers induced per anther were extremely low following 6kR of 60Co ?-ray radiation. A white flower mutant appeared in the induced progenies. The tobacco leaf quality of this mutant were significantly improved as compared with its parental line. The mutant line has been tested and proved to have commercial value though the resistance to the black shank of tobacco slightly decreased as compared with the parental line

1991-01-01

23

Evaluation of anther culture methods and androgenic capacity of wheat mutant lines  

International Nuclear Information System (INIS)

Several experiments were conducted with the aim of obtaining haploid plants via anther culture of Chilean spring wheat genotypes. The first experiments compared five culture media and the effect of different incubation conditions on anthers of the genotypes Austral-UACH, Carahue-INIA, Dalcahue-INIA and Pavon 76. The low androgenic response obtained in these experiments, with a maximum of 1.78% callus induction, resulted in a change in methodology. In other experiments, the effect of P-4 callus induction medium and 190-2 plant regeneration medium on M2 and M3 mutant lines of As-Baer, Carahue-INIA, Dalcahue-INIA and Pavon 76 were compared. The effect of two sterilization systems was also studied. These experiments gave a maximum of 55.7% callus formation and a variable organogenesis in three genotypes. Dalcahue-INIA irradiated with 20 krad gamma rays (200 Gy) gave a good organogenic response. The percentage of albino plants ranged between 0 and 83.3% of the total regenerants. (author). 24 refs, 5 tabs

1996-01-01

24

Pretreatment Stress Enhances Embryogenic Callus Production in Anther Culture of Sturt’s Desert Pea (Swainsona formosa)  

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The aims of the experiment were to investigate the effect of pretreatment stress on the proliferation of anther-derived embryogenic callus, and its subsequent embryo regeneration in Swainsona formosa. Anthers were pretreated in starvation medium at cold (4 oC) temperature and cultured. Cultures were initially placed in darkness for four weeks, followed by 16-h photoperiod at 25 + 1 oC. The stress pretreatment was found to enhance embryogenic callus formation on cultured anthers. Further, soma...

2007-01-01

25

Improvement of rice anther culture and application of the technique in mutation breeding  

International Nuclear Information System (INIS)

The ability of callus formation and green plant regeneration was very different for different rice type and varieties in anther culture. The differentiation and regeneration of green plants were obviously improved when the rice anthers at about 30 d after culture on induction medium were irradiated with 20 Gy of ?-rays and calli were cultured on the differentiation medium containing 30 mg/L colchicines. The stimulation effect of ?-irradiation combined with colchicines was much better than that of their single use. Mutation frequency and selective efficiency in M_2 were obviously increased by application of the technique

2001-04-01

26

Effect of selected factors on the effectiveness of Capsicum annuum L. anther culture.  

Science.gov (United States)

The primary aim of the study was to establish the effectiveness of induced androgenesis in in vitro anther culture of two pepper (Capsicum annuum L.) breeding lines--ATZ1 and PO, and a hybrid between these two lines (ATZ1 x PO)F1. Anther culture was maintained according to the method developed by Dumas de Vaulx et al. (1981) with some modifications. The experiment revealed that the effectiveness of androgenesis ranged from 4 %; for the ATZ1 line to 1.5 %; for the (ATZ1 x PO)F1 and strongly depended on the developmental stage of flower buds, as well as the conditions for anther culture maintenance. The development of androgenic embryos was successfully induced only in anthers which originated from the flower buds with petals equal or slightly longer than sepals and there was a clear relationship between the length of the period of anther induction on CP medium and the level of kinetin in R1 regeneration medium. PMID:16682751

Nowaczyk, Pawe?; Kisia?a, Anna

2006-01-01

27

Induced mutations and Anther culture for sesame improvement  

International Nuclear Information System (INIS)

Seeds of two Sri Lankan sesame (Sesamum indicum L.) cultivars MI 2 and MI 3 and of UCR82-203 NS which has indehiscent capsules were treated with gamma rays, ethyl methanesulphonate and diethyl sulphate. Selections were made in segregating populations for improved yield components and morphological characters. Radiation sensitivity studies indicated that the seeds of MI 3 variety were more resistant to irradiation than MI 2. The M_1 plants also showed varietal differences in growth reduction. Fifty percent growth reduction for plant height in MI 2 was in the range of 500 - 600 Gy and that for MI 3 was 750 - 1000 Gy. Promising mutants after screening in preliminary trials were tested for yield and adaptability in multilocational trials in different agro-climatic zones. A wide variation and increased mean values of yield and components were recorded in selected mutants in the preliminary trials. Two mutants, MB 29 and MB 33, consistently outyielded the recommended cultivar MI 3 in regional trials. The mutant MB 13 was also promising. MB 29 and MB 29w have a brittle seed coat easy for decortication. A number of mutants with improved characters have been isolated, characterized and included in the cross-breeding programmes. Mutants MB 29 and MB 33 recorded better germination than MI 2 under high osmotic pressure and should be tested for tolerance to drought at early growth phases. The shoot/root ratio was lease in MB 29, MB 1 and MB 1-1. The shortest and more synchronous flowering period recorded in MB 29 and C 10 is important in reducing shattering losses and escaping from drought at flowering stage, Two mutants which have lost the undesirable effects associated with the indehiscent character in UCR82-203 NS were later found to have lost the indehiscent character too, suggesting that the undesirable effects of the indehiscent (id id) locus are pleiotropic. Anther culture studies were undertaken with the objective of using doubled haploids for sesame improvement. 25 refs, 2 figs, 7 tabs

1994-12-01

28

Inheritance of callus formation ability in anther cultures of rice, Oryza sativa L.  

Science.gov (United States)

Inheritance of ability to form callus in rice anther culture was studied using the diallel technique. Anthers containing uninucleate microspores from two japonica cultivais ('Minehikari' and 'Taipei 309'), two indica cultivars ('Mingolo' and 'Suweon 290'), and 12 F1's of the diallel crosses involving these four parents were cultured on Chaleffs R2 medium and evaluated for callus induction. The parents showed significant differences in anther callus formation, from 41.9% ('Taipei 309') to 0% ('Suweon 290'). Callus induction ability was inherited as a recessive character conditioned by a single block of genes. Additive gene effects were predominant. The japonica types seemed to be good combiners for callus induction. The order of dominance among the four parents was 'Suweon 290', 'Mingolo', 'Minehikari' and 'Taipei 309'. PMID:24254166

Miah, M A; Earle, E D; Khush, G S

1985-05-01

29

Production of haploids of neem (Azadirachta indica A. Juss.) by anther culture.  

Science.gov (United States)

Androgenic haploids of the neem tree (Azadirachta indica A. Juss.) were produced by anther culture at the early- to late-uninucleate stage of pollen. Haploid formation occurred via callusing. The best medium for inducing callusing in the anther cultures was Murashige and Skoog's basal medium (MS) (9% sucrose) supplemented with 1 microM 2,4-D, 1 microM NAA and 5 microM BAP, while anther callus multiplied best on MS medium supplemented with 1 microM 2,4-D and 10 microM Kn. These calli differentiated shoots when transferred to a medium containing BAP; 5 microM BAP was optimum for young calli (75% cultures differentiated shoots), but older calli showed the best regeneration with 7.5 microM BAP. Shoots elongated at a lower concentration of BAP-0.5 microM. These shoots were multiplied by forced axillary branching and rooted in vitro. The plants were subsequently established in soil. Of the plants that regenerated from anther callus 60% were haploid, 20% were diploid and 20% were aneuploid. PMID:12789427

Chaturvedi, R; Razdan, M K; Bhojwani, S S

2003-02-01

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A Comparison between Wheat and Maize Cross and Anther Culture Method for Production of Wheat Haploid Plants  

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The significance of haploid plants as genetic and plant breeding tools has been recognized for a long time. Haploid production techniques including anther culture, isolated microspore culture and intergeneric hybridization between wheat × Hordeum bulbosum and wheat × maize have been used to produce homozygous lines which accelerate breeding programs. In this study, wheat × maize hybridization and anther culture techniques were used for haploid production in six wheat genotypes. The results...

2004-01-01

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Calli Induction through Anther Culture in Peach-Tomato Plants (Solanum sessiliflorum Dunal  

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Full Text Available Flower buds from peach tomato plants (Solanum sessiliflorum were collected to the establishment of a protocol of calli induction from anthers culture. Aseptic cultures were achieved after the immersion of explants into 70% ethanol for 45 sec followed by 0.8% sodium hypochlorite for 5 min. Cultivated anthers developed 50 and 70% of calli with 0.1 mg L-1 indole-3-acetic acid (IAA+5 mg L-1 kinetin (KIN and 0.1 mg L-1 indole-3-acetic acid (IAA+10 mg L-1 kinetin (KIN, respectively. The calli oxidation increased in treatments free of activated charcoal, daily pre-refrigeration (4°C for 48 h and 20 mg L-1 of kinetin (KIN. The best plant growth regulator concentration for stimulating calli formation was 5 mg L-1 of kinetin (KIN.

I. Romani

2009-01-01

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GENETIC DIVERSITY ANALYSIS OF ANTHER CULTURE DERIVED RICE PLANTS USING MOLECULAR MARKERS  

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Random amplified polymorphic DNA (RAPD) analysis and inter-simple sequence repeats (ISSR) primers were used to determine the occurrence and extent of variation in rice (Oryza sativa L.) plants regenerated from anther culture. Genetic diversity among 27 regenerants of the cross CO43/Nootripathu and their parents were assessed using 25 RAPD primers and 19 ISSR primers. RAPD primers used in the study produced 285 polymorphic markers (81.65% polymorphism) and ISSR primers produced 201 polymorphic...

2013-01-01

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Combining Ability and Heritability of Callus Induction and Green-Plant Regeneration in Rice Anther Culture  

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Full Text Available This study was conducted to determine the inheritance of callus induction and plant regeneration in rice anther culture. Low efficiencies of callus induction and green-plant regeneration have limited the application of anther culture in plant breeding programs. Four parents along with six F1 genotypes derived from a four-parent incomplete diallel mating set of two commercial lines (Amol2 and Amol3 and two local cultivars (Ghasroddashti and Rashti were evaluated for their callus induction and plant regeneration abilities. The results showed that the callus induction, green-plant regeneration and the effects of genotype and genotypexmedium interaction were significant (p<0.01. The local cultivars generally had a higher percent callus induction, plant regeneration and number of calli producing green plants than the commercial lines. The parents showed significant difference in anther callus formation, from 4.01% (Amol2 to 22.26% (Rashti. Combining ability analysis demonstrated the predominance of additive gene effects in the control of both characters with the local cultivars having higher combining ability for green-plant regeneration. Also gene action to be partially dominant for both characters. Combining ability analysis revealed that both additive and dominant gene effects are important in controlling callus induction and green-plant regeneration in rice.

N. Bagheri

2008-01-01

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The haploid embryoids development in anther culture of transformed tobacco (Nicotiana tabacum L.  

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Full Text Available Induction of pollen embryogenesis was used for the test of cytokinin influence on the development of pollen grain. Gene for maize cytokinin-specific ?-glucosidase were introduced into tobacco genome together with the methotrexate resistance marker (Brzobohatý et al. 1994. Anther culture of T1 generation of transformed Nicotiana tabacum L. plants revealed that high activity of ?-glucosidase caused a reduced regeneration of pollen embryoids. The stages of pollen embryoid development were comparable with those of zygotic embryos. Optimal nutritive medium contained charcoal and chelated iron. The absence of iron in the initiation medium caused a distinct decrease of pollen embryoid regeneration.

Jaroslava Dubová

1996-06-01

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Pretreatment Stress Enhances Embryogenic Callus Production in Anther Culture of Sturt’s Desert Pea (Swainsona formosa  

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Full Text Available The aims of the experiment were to investigate the effect of pretreatment stress on the proliferation of anther-derived embryogenic callus, and its subsequent embryo regeneration in Swainsona formosa. Anthers were pretreated in starvation medium at cold (4 oC temperature and cultured. Cultures were initially placed in darkness for four weeks, followed by 16-h photoperiod at 25 + 1 oC. The stress pretreatment was found to enhance embryogenic callus formation on cultured anthers. Further, somatic embryos were successfully regenerated from embryogenic callus upon transferred onto regeneration medium supplemented with 1% sucrose and 4.63 ?M kinetin, and later plantlets were obtained. Meanwhile, nonembryogenic callus continued to grow resulting in more callus mass without showing any embryoid initiation.

ZULKARNAIN

2007-03-01

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In vitro Plant Regeneration Through Anther Culture of Some Iranian Local Rice (Oryza sativa L. Cultivars  

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Full Text Available In this study, effect of different genotypes, different callus induction and regeneration media were investigated using seven Iranian local rice. Anthers were cultured on N6, Fj and L8 media containing the same hormonal combination 3 mg L-1 NAA, 0.5 mg L-1 Kn and 0.5 mg L-1 2, 4-D and incubated at 25± 1° C in dark for callus induction. All varieties in L8 medium, five varieties in Fj medium and six varieties in N6 medium produced highest percentage of callus. Calli induced in different induction media were transferred to SK 11 and N 19 medium and incubated at 25± 1° C in light for plantlet regeneration. Among seven varieties upon transfer to SK 11 medium, highest percentage (40% of green plants were produced in Hassani and in N 19 medium the highest percentage (15.78 of green plants and albino plants (21.05 were produced in Anbarbo. The finding in the present investigation showed that the successfully emberyogenesis and green plant regeneration in rice anther culture dependent on medium culture components and are affected by the genetic mack-up of the plants.

Reza Talebi

2007-01-01

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In vitro plant regeneration through anther culture of some Iranian local rice (Oryza sativa L.) cultivars.  

Science.gov (United States)

In this study, effect of different genotypes, different callus induction and regeneration media were investigated using seven Iranian local rice. Anthers were cultured on N6, Fj and L8 media containing the same hormonal combination 3 mg L(-1) NAA, 0.5 mg L(-1) Kn and 0.5 mg L(-1) 2, 4-D and incubated at 25 +/- 1 degree C in dark for callus induction. All varieties in L8 medium, five varieties in Fj medium and six varieties in N6 medium produced highest percentage of callus. Calli induced in different induction media were transferred to SK 11 and N 19 medium and incubated at 25 +/- 1 degree C in light for plantlet regeneration. Among seven varieties upon transfer to SK 11 medium, highest percentage (40%) of green plants were produced in Hassani and in N 19 medium the highest percentage (15.78) of green plants and albino plants (21.05) were produced in Anbarbo. The finding in the present investigation showed that the successfully emberyogenesis and green plant regeneration in rice anther culture dependent on medium culture components and are affected by the genetic mack-up of the plants. PMID:19093446

Talebi, Reza; Rahemi, Mohammad Reza; Arefi, Habibolah; Nourozi, Mohammad; Bagheri, Nadali

2007-06-15

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In vitro Plant Regeneration Through Anther Culture of Five Rice Varieties  

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Full Text Available Anthers of five rice varieties viz. BR-5, BR-31, BR-34, BR-37 and BR-38 were cultured for callus induction and plant regeneration. Anthers were cultured on N6, Z2 and R2 media containing the same hormonal combination 2.5mg/l NAA, 0.5mg/l Kn and 0.5mg/l 2.4-D and incubated at 25 ± 1oC in dark for callus induction. All the varieties in Z2 medium, two varieties in N6 medium and only one variety in R medium produced callus. Out of all responding varieties BR-38 produced highest percentage of callus. Calli induced in different induction media were transferred to MS medium supplemented with 2.0 mg/l BAP + 0.5 mg/l Kn + 1.0 mg/l NAA and 1.0 mg/l Kn + 1.0 mg/l NAA and incubated at 25 ± 1oC in light for plantlet regeneration. Green plantlets appeared within 15-30 days of culture and highest number of regenerated green (33.32% and albino (11.27% plantlets were produced in BR-37.

M. Asaduzzaman

2003-01-01

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Androgenesis in chickpea: anther culture and expressed sequence tags derived annotation.  

Science.gov (United States)

Double haploid technique is not routinely used in legume breeding programs, though recent publications report haploid plants via anther culture in chickpea (Cicer arietinum L.). The focus of this study was to develop an efficient and reproducible protocol for the production of double haploids with the application of multiple stress pre-treatments such as centrifugation and osmotic shock for genotypes of interest in chickpea for their direct use in breeding programs. Four genotypes, ICC 4958, WR315, ICCV 95423 and Arearti were tested for anther culture experiments. The yield was shown to be consistent with 3-5 nucleate microspores and 2-7 celled structures with no further growth. To gain a further insight into the molecular mechanism underlying the switch from microsporogenesis to androgenesis, bioinformatics tools were employed. The challenges on the roles of such genes were reviewed while an attempt was made to find putative candidates for androgenesis using Expressed Sequenced Tags (EST) and interolog based protein interaction analyses. PMID:24597152

Panchangam, Sameera Sastry; Mallikarjuna, Nalini; Gaur, Pooran M; Suravajhala, Prashanth

2014-02-01

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Stimulation effects of ?-irradiation combined with colchicine on callus formation and green plant regeneration in rice anther culture  

International Nuclear Information System (INIS)

The ability of callus formation and green plant regeneration was very different for various rice types and varieties in rice anther culture. It was quite effective that rice anthers were irradiated with 10-40 Gy of ?-rays after 30 d incubation on induction medium and calli were treated on differentiation medium contained 10-75 mg/L of colchicine for increase of callus formation and green plant regeneration. Among these treatments, 10 Gy of ?-rats was the best for callus formation, and 20 Gy of ?-rays or 30 mg/L of colchicine was the most favourable for green plant regeneration. The simulation effect of 20 Gy of ?-irradiation combined with 30 mg/L of colchicine on green plant regeneration was much better than that of their separate use in rice anther culture

1999-01-01

 
 
 
 
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Effects of gamma irradiation and other factors on the induction of calli and regeneration of greed plants in rice anther culture  

International Nuclear Information System (INIS)

Induction of calli and regeneration of green plantlets in anther culture of rice variety, Taipei 309, were greatly affected by gamma irradiation and other factors. Callus formation from the anthers of mid-uninucleate stage pre-incubated at 7 degree C for 5 days were 0.4 and 0.6 times higher than those of the anthers of late uninucleate stage and non-treated control. However, the number of calli with green plantlets and the number of regenerated green plantlets per 100 anthers cultured were 3.1 and 4.1 times higher for the calli from the anthers at late-uninucleate stage than those from the anthers at mid-uninucleate stage; the calli with green plantlets increased with the time of anther incubation (35 days, 7.7%; 45 days, 10.6%; 55 days, 16.7%). However, the ability was lost for all calli 65 days after incubation. The highest ability of green plant regeneration for the calli transferred by 35 days after incubation and differentiated green plantlets at about 25th day after transfer to regeneration medium, which reached 443.6 plants per 100-anthers cultured and was much higher than that of the calli transferred and differentiated green plantlets later. 20 Gy of gamma irradiation at the time when about 5% anthers produced calli by 35 days after incubation has a great positive effects on induction of calli, differentiation and regeneration of green plantlets. The number of callus formation, calli with green plantlets and green plantlets regenerated per 100-anthers cultured were 0.5, 22 and 306 times higher than those of non-irradiated control respectively

1997-03-01

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Rice anther culture: callus initiation and androclonal variation in progenies of regenerated plants.  

Science.gov (United States)

Anthers from rice (Oryza sativa L.) subspecies japonica initiated more callus than their indica or indica x japonica counterparts. A mild stress, either by slow desiccation or heat shock, prior to the plating of anthers enhanced the ability to initiate callus. Slow dessication of anthers enhanced the ability of the japonica anthers to initiate callus even in medium that was supplemented with NaCl. The ability to initiate callus by the anthers plated on NaCl-supplemented medium decreased as the NaCl level in the medium increased. Among the regenerated plants 2.5% were albino and another 2% were haploid. Androclonal variation for tiller numbers, shoot height, plant dry matter and flowering were noticed in the progenies of the regenerated plants. PMID:24185451

Sathish, P; Gamborg, O L; Nabors, M W

1995-04-01

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GENETIC DIVERSITY ANALYSIS OF ANTHER CULTURE DERIVED RICE PLANTS USING MOLECULAR MARKERS  

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Full Text Available Random amplified polymorphic DNA (RAPD analysis and inter-simple sequence repeats (ISSR primers were used to determine the occurrence and extent of variation in rice (Oryza sativa L. plants regenerated from anther culture. Genetic diversity among 27 regenerants of the cross CO43/Nootripathu and their parents were assessed using 25 RAPD primers and 19 ISSR primers. RAPD primers used in the study produced 285 polymorphic markers (81.65% polymorphism and ISSR primers produced 201 polymorphic markers (79.37% polymorphism. The number of markers produced per primer ranged from 4-27 in case of RAPD with a mean of 14.04 and 7-23 in case of ISSR with a mean of 13.05. Dendrograms were constructed using similarity index values. RAPD markers grouped the 27 regenerants (A0 generation and their parents into four clusters and ISSR markers into three clusters. The Polymorphism information content (PIC values ranged from 0.702 to 0.952 with a mean of 0.887 for RAPD markers. In ISSR analysis, the mean PIC value was 0.891 and the highest and lowest PIC values were 0.940 and 0.832 respectively. In the present study, RAPD markers were able to reveal greater genetic diversity among the regenerants screened than ISSR markers.

Hemaprabha K

2013-07-01

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Ensuring Reproduction at High Temperatures: The Heat Stress Response during Anther and Pollen Development  

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Full Text Available Sexual reproduction in flowering plants is very sensitive to environmental stresses, particularly to thermal insults which frequently occur when plants grow in field conditions in the warm season. Although abnormalities in both male and female reproductive organs due to high temperatures have been described in several crops, the failure to set fruits has mainly been attributed to the high sensitivity of developing anthers and pollen grains, particularly at certain developmental stages. A global view of the molecular mechanisms involved in the response to high temperatures in the male reproductive organs will be presented in this review. In addition, transcriptome and proteomic data, currently available, will be discussed in the light of physiological and metabolic changes occurring during anther and pollen development. A deep understanding of the molecular mechanisms involved in the stress response to high temperatures in flowers and, particularly, in the male reproductive organs will be a major step towards development of effective breeding strategies for high and stable production in crop plants.

Filomena Giorno

2013-07-01

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Effects of Genotype on Induction of Callus and Plant Regeneration Potential in vitro Anther Culture of Rice (Oryza sativa L.  

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Full Text Available The present studies were carried out to evaluate the response of anthers of six rice genotypes to callus induction and plant regeneration. For callus induction Z2 media supplemented with 2, 4-D 0.5 mg l-1, NAA 2.5 mg l-1 and Kinetin 0.5 mg l- was used. Of the six genotypes, five gave good callusing response. Highest callus induction was observed in BRRI Dhan-29 (8.06% and lowest in BR-10 (1.42%. Callus induction frequency varied from 1.42-8.06% depending on genotypes. Modified MS medium supplemented with Kinetin 0.5 mg l-1, BAP 2 mg l-1 and NAA 1.0 mg l-1 was used for plant regeneration. The results showed a significant genotypic difference in callus induction and plant regeneration. The regeneration of plantlet from anther derived calli ranged from 57-75% conclusion.

Sharmin Shahnewaz

2004-01-01

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Breeding evaluation of pepper lines obtained by in vitro anther culture  

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Full Text Available The comparative breeding evaluation was carried out with six advanced pepper lines (Capsicum annuum L. with androgenic origin and their initial pepper variety Hebar during the period 2008 - 2010 in field conditions at Plovdiv, Bulgaria. The genotypes were characterized by total and standard yield, plant height and fruit traits: length, width, wall thickness and weight. The response of two lines (4 and 6 and control variety to the Verticillium wilt was also investigated on artificial infected background. According to the results of the experimental work standard and total yield in all androgenic lines were higher compared to the initial variety but significant differences were established only for lines 1, 2, 4 and 6. Line 6 was characterized with the highest standard yield (4009 kg/da followed by line 2 (3829 kg/da. They exceeded variety Hebar with 42.26% and 35.89%, respectively. Line 2 formed the heaviest (61.31 g and longer (11.24 cm fruits than most studied genotypes. Anther-derived lines were also with a good uniformity by studied traits. In line 6 was registered lower index of infestation byVerticillium dahliae Kleb. than the control during the investigated period. These perspective lines will be included as valuable genetic resources for future pepper breeding programs for development of new varieties.

Todorova Velichka

2013-01-01

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Recovery of Green Plantlets from Albino Shoot Primordia Derived from Anther Culture of Indica Rice (Oryza sativa L.).  

Science.gov (United States)

A simple method was developed to permit albino plant regeneration from anther culture of Hobigonj Boro (Hbj B) IV and Hbj B VI, two local varieties of aromatic indica rice from Bangladesh. Three crucial factors were identified for the albino shoot primordia to change into green plantlets in culture; components of M10 induction medium, callus size (range 0.2-0.4 cm long) and height of shoot primordia (range 2-3 mm). Immediate transfer of shoot primordia (2-3 mm) from M10 medium to regeneration medium followed by continuous incubation under fluorescent light (100-lux, 25±1°C) triggered albino shoot primordia to turn green in 2-3 days. Callus size did not show any effect on the change. Albino plantlets derived from anther callus cultured in KA, KB, KC, KD and KE media did not recover in both the varieties. Transfer of albino shoot primordia shorter or longer than 2-3 mm from the above 5 cultures to regeneration medium did not cause the shoot primordia to turn green. 100% albino shoot primordia initiated from Hbj B VI and 79% from Hbj B IV in M10 medium changed to green plantlets upon transfer to regeneration medium. Subsequent culture and subculture of green plantlets showed rapid formation of many new green plantlets. PMID:24575205

Mohiuddin, Abul Kashem Md; Karim, Nilufer Hye; Sultana, Shahanaz; Ferdous, Zannatul

2011-05-01

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MORPHOGENETICAL AND HISTOLOGICAL STUDIES OF „IN VITRO” ANTHER CULTURES OF BRASSICA OLERACEA L.  

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Full Text Available The anthers were inoculated on 8 hormonic variants of MS (Murashige-Skoog, 1962 medium and on one variant of B5 (Gamborg, 1968 slightly changed medium formula. The main morphogenetic reaction was callus formation. The callus’s consistency and colour differed depending on the hormonic variant. The friable callus for all the tested genotypes had caulogenetic capacity. Its passage on differentiation media comprising cytokinins led to new shoots formation, the intensity of this phenomenon varied with the genotype and with the initial medium that provided the respective callus. The histological studies of calluses or of anther shoots pointed out callus structure and the numerous histogenetic stages due to growth regulators, as well as in vitro regenerated shoots’ structure.

Gogu Gheorghita

2005-08-01

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Callus and Green Spot Formation From Anther Culture of Chili Mutant Lines (Capsicum Annum.L) Using in-vitro Culture  

International Nuclear Information System (INIS)

Callus and green spot formation from anther culture of chili mutant lines (Capsicum annum.L) were carried out using in-vitro culture. Two kinds of different media based on hormonal composition were used for callus induction. A half of an quantities were directly cultured on callus induction medium, while rest of them were treated with cold shock (4oC) for 3 and 6 days subsequently cultured on callus induction medium. The highest callus formation was observed in culture from Ac medium containing I mg/l 2,4-D and 0,1 mg/l kinetin and were obtained from 0 days cold shock with chili without irradiation (Kr 0) 30%, chili mutant lines with irradiation dose 20 Krad (Kr 20) 25% and chili mutant lines with irradiation dose 40 Krad (Kr 40) 30% respectively. While cold shock for 3 days increasing 15 % callus formation from Kr 40 mutant lines

2001-11-06

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Anthere culture of tetraploid somatic hybrids as a crucial tool for starting Practical introgression breeding from allied species in eggplant (S. melongena L.)  

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The major limits for practical exploitation of the somatic hybrids between eggplant and its wild relatives has been their sterility and tetraploidy which have prevented their incorporation into breeding programs. We successfully employed anther culture to bring back the ploidy level to the diploid status of tetraploid interspecific hybrids between eggplant and the allied species S. integrifolium (=S. aethiopicum gr aculeatum) and S. aethiopicum gr gilo. Both the relative species are resistant...

Valentino, Danila; Tamietti, Giacomo

2007-01-01

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Investigation of the effect of 137Cs treatment on callus induction and plant regeneration anther culture in rice  

International Nuclear Information System (INIS)

Anthers at a single-nucleus stage of dihaploid L44 line have been treated with 1000, 2000 and 3000 R (137Cs). Irradiation has shown general inhibition effect on the induction of callus of the anthers inoculated. It is thought that the treatment effect is connected with the switching of the microspores from gametophytous to sporophytous type of development. The number of the albino regenerates increases along with the increase in irradiation dose. It could be explained by the mutation effect of 137Cs on the multiple genes controlling the pigment-protein complex. 2 tabs., 10 refs

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Histochemical and immunohistochemical identification of laticifer cells in callus cultures derived from anthers of Hevea brasiliensis.  

Science.gov (United States)

Laticifers are highly specialized cells present in over 20 plant families. They are well defined in planta. In vitro development of laticifers was also observed in some plants, but uncertain in the callus cultures of rubber tree, one of the most economically important latex producing plants. In the present study, we provide evidence that laticifer cells present in the callus cultures of rubber tree by histochemical and immunohistochemical studies. They present in the callus mainly as separate non-elongated form, a novel morphology different from the morphology of laticifer cells in planta, excluding their origin from explants. The occurring frequency of laticifer cells in the callus was genotype-dependent and negatively correlated with the somatic embryogenetic ability, suggesting that the presence of laticifer cells in the callus inhibit somatic embryogenesis in tissue culture of rubber tree. The genotypes PR107, RRIM600, Reyan8-79, and Reyan7-33-97 with lower embryogenetic ability compared to Haiken 2 had more laticifer cells, and laticifer clusters were only observed in these genotypes. PMID:21301851

Tan, Deguan; Sun, Xuepiao; Zhang, Jiaming

2011-06-01

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Anther development stage and gamma radiation effects on tomato anther-derived callus formation  

International Nuclear Information System (INIS)

Two experiments were carried (I) to determine tomato anther development stage influence on callus production; and (II) to investigate gamma radiation effects on anther culture. In the first experiment, anthers of a tomato hybrid (IPA 5 x Rotam 4-F1) were grown on three media. Although calli were induced at all stages of anther development, varying from prophase I to mono nucleate microspore, callus frequency decreased as anther development progressed and calli induction were not significantly affected by all media tested. Anthers containing prophase I meiocytes produced the highest calli frequency. Anther and flower bud length both were significantly correlated with anther development stage. In the second experiment, seed and floral buds of tomato hybrids IPA 5 x Rotam 4 (F2), IPA 6 x Rotam 4 (F2) and IPA 8 x 217.1 (F2) were submitted to gamma-ray and anthers were plated on two media described by Gresshoff and Doy (1972) supplemented with 2.0 mg L-1 NAA + 5.0 mg L-1 KIN and 2.0 mg L-1 NAA + 1.0 mg L-1 KIN. No significant differences for genotype and dosage testes were found for calli formation. (author)

1999-01-01

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[Anther culture generated stem borer-resistance DH lines of Minghui 81(Oryza sativa L. subsp. indica) expressing modified cry1Ac gene].  

Science.gov (United States)

2600 Anthers from T0 modified cry1 Ac-transgenic rice lines of Minghui 81, an elite restoring line of commercial CMS indica hybrid rice, were cultured on SK3 media. 83 green plantlets were recovered, 43 double haploid (DH) and 40 haploid among them. Results of PCR analyzes indicated that 55 plants of 83 were harbored the cry1Ac gene, and the ratio of cry1Ac-positive against cry1Ac-negative was 2:1 (55/28). 36 putative transgenic DH plants were further confirmed by Southern blot. ELISA detection showed that Cry1Ac level in different transgenic rice plants of the same cry1Ac-DH clone was almost equal and the highest one amount to 0.25% of the total soluble protein. Pest insect-resistant bioassay at field trials demonstrated that some of the homozygous cry1Ac-transgenic rice plants not only showed high-level resistance against striped stem borer (Chilo suppressalis) but also retained elite agronomy characters. These results demonstrated that rice anther culture has a great value in rice molecular breeding. PMID:12385240

Zeng, Qian-Chun; Wu, Qian; Feng, De-Jiang; Zhou, Kai-Da; Liu, Xiang; Zhu, Zhen

2002-07-01

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Nuevos genotipos de arroz resistentes a la Piriculariosis obtenidos por cultivo de anteras / New blast resistant rice genotypes obtained by and anthers culture  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish En la Estación Experimental del Arroz Los Palacios, perteneciente al Instituto Nacional de Ciencias Agrícolas de Cuba (INCA), se efectuaron cruzamientos entre cuatro cultivares resistentes a la Piriculariosis y seis de buen comportamiento agronómico y las anteras de las plantas F2 fueron cultivadas [...] in vitro para evaluar la formación de callos en tres medios líquidos: N6-1, N6-m y NL, así como la regeneración de plantas verdes y albinas, en el medio MS. Las dos primeras generaciones de las nuevas líneas obtenidas fueron evaluadas para caracteres agronómicos y la segunda generación, además, para resistencia frente a la Piriculariosis. Las líneas que combinaron resistencia a la Piriculariosis y buenos caracteres agronómicos fueron evaluadas en condiciones de infección natural, con alta presión del patógeno. La utilización de la técnica del cultivo de anteras mostró alta dependencia del genotipo y el medio de cultivo. Con el medio NL se lograron los valores más altos para la formación de callos. Se obtuvieron nuevos genotipos resistentes a la Piriculariosis y de alto rendimiento agrícola. Abstract in english Crosses were made between four blast resistant and six rice varieties of good agronomic performance, at the Los Palacios Rice Research Station of the National Agricultural Sciences Institute of Cuba (INCA) and the anthers from F2 plants were in vitro culture using three liquid media: N6-1, N6m, and [...] NL, for callus formation and after plants regenerations using MS medium. The first two generations of breeding lines were evaluated for agronomic characters and the second generations, also, for Blast resistant. The lines that combined resistance to Blast and good agronomic performance were evaluated under high pressure of natural Blast infection conditions. The success rate of anther culture was highly dependent on the genotype and culture media used. NL medium led to the highest callus formation values. In the process, new blast resistant and high yielding genotypes were obtained.

Noraida de Jesús, Pérez; María Caridad, González; Rodolfo I, Castro; Manuel, Aguilar.

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Efficient callus induction and plant regeneration from anther of Chinese narcissus (Narcissus tazetta L. var. chinensis Roem).  

Science.gov (United States)

Callus culture has, to date, been reported only in a few species of Narcissus. We used anthers of Chinese narcissus (Narcissus tazetta L. var. chinensis Roem) as explants for callus induction and plant regeneration. A high percentage of anthers at the early- to mid-uninucleate microspore stage were responsive on the basal MS medium supplemented with 0.5-1 mg l(-1) 2,4-dichlorophenoxyacetic acid and 0.5-2 mg l(-1) 6-benzyladenine under dark conditions. Calli were initiated from anther connective tissue or anther wall tissue, and no division of microspores occurred during callus formation, as determined by histological observation. Using 20 random amplified polymorphic DNA primers, we verified the genetic integrity of the anther-derived plants of Chinese narcissus with respect to the donor plants. These results suggest that anther culture in vitro can provide an efficient new micropropagation technique for Chinese narcissus as well as a new strategy for in vitro mass propagation of other daffodils. PMID:15843934

Chen, LinJiao; Zhu, XueYi; Gu, Li; Wu, Jian

2005-09-01

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Haplodiploid androgenetic breeding in oat: genotypic variation in anther size and microspore development stage Melhoramento por haplodiploidização androgenética: variação genotípica no tamanho das anteras e no estágio de desenvolvimento dos micrósporos em aveia  

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Oat (Avena spp.) is poorly responsive to the haplodiploidization process, which leads to the production of homozygous lines in one step, increasing breeding efficiency. Androgenetic haploids in small grain cereal crops are obtained from microspores cultured at the mononucleate stage, which can be identified by the size of anthers. In order to identify the appropriate anther size for in vitro culture, microspore cytological analyses were made in Avena sativa cultivars UPF 7, UPF 18, UFRGS 14, ...

Taniela De Cesaro; Maria Irene Baggio; Silvia Andréia Zanetti; Marilei Suzin; Lizete Augustin; Sandra Patussi Brammer; Edson Jair Iorczeski; Sandra Cristina Kothe Milach

2009-01-01

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New players unveiled in early anther development.  

Science.gov (United States)

Anther development is an important process for the successful sexual reproduction in plants. Whereas the regulation of the late stages of anther development is quite well described in A. thaliana, little is known about the regulation of the early stages of this process. Two novel groups of factors involved in these early stages have recently been described, namely ROXYs, members of the Glutaredoxin (GRX) family of small and ubiquitous oxidoreductases involved in various cellular and stress-related responses, and SBP-box Genes. ROXYs belong to the CC-type of GRXs with a CCXC active motif and are specific for higher plants. SBP-box genes encode for SQUAMOSA PROMOTER BINDING PROTEIN transcription factors, many of which are targeted by miR156 and miR157. Strikingly, both the enzymes and the transcription factors represent evolutionary conserved gene families and loss-of-function of these genes exhibits similar anther phenotypes, e.g. arresting sporogenous cell formation and missing pollen sacs. This mini-review gives an overview of how these factors affect early anther development and discusses a possible relationship between these factors and other known early anther genes. PMID:21633200

Xing, Shuping; Salinas, María; Huijser, Peter

2011-07-01

59

Improved rate of callus induction from rice anther culture following microscopic staging of microspores in iron alum-haematoxylin.  

Science.gov (United States)

High frequencies of callusing were obtained in indica rice from the microspores which were staged in acetic acid iron alum-haematoxylin stain prior to culture on G5 medium. Two local varieties, 'Khonorullo' and 'Namyi', and two advance pre-release cultures, 'PK 1-1-3' and 'PK 12-22', were used in this investigation. All the cultures exhibited a wide adaptation to varying medium; however, the frequency of callusing was highest (45.5%) in 'PK 1-1-3' followed by 'PK 12-22' (32.4%) and 'Khonorullo' (31.6%). Cold shock (10 °C) for 11 days enhanced the frequency of callusing by 200% in 'Khonorullo'. PMID:24241463

Gupta, H S; Borthakur, D N

1987-05-01

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Anther development stage and gamma radiation effects on tomato anther-derived callus formation; Efeitos do estadio de desenvolvimento da antera e da radiacao gama na formacao de calos derivados de anteras de tomate  

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Two experiments were carried (I) to determine tomato anther development stage influence on callus production; and (II) to investigate gamma radiation effects on anther culture. In the first experiment, anthers of a tomato hybrid (IPA 5 x Rotam 4-F{sub 1}) were grown on three media. Although calli were induced at all stages of anther development, varying from prophase I to mono nucleate microspore, callus frequency decreased as anther development progressed and calli induction were not significantly affected by all media tested. Anthers containing prophase I meiocytes produced the highest calli frequency. Anther and flower bud length both were significantly correlated with anther development stage. In the second experiment, seed and floral buds of tomato hybrids IPA 5 x Rotam 4 (F{sub 2}), IPA 6 x Rotam 4 (F{sub 2}) and IPA 8 x 217.1 (F{sub 2}) were submitted to gamma-ray and anthers were plated on two media described by Gresshoff and Doy (1972) supplemented with 2.0 mg L{sup -1} NAA + 5.0 mg L{sup -1} KIN and 2.0 mg L{sup -1} NAA + 1.0 mg L{sup -1} KIN. No significant differences for genotype and dosage testes were found for calli formation. (author)

Brasileiro, Ana Christina R.; Willadino, Lilia [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Lab. de Cultura de Tecidos Vegetais. E-mail: lilia@truenet.com.br; Guerra, Marcelo [Pernambuco Univ., Recife, PE (Brazil). Dept. de Botanica. Lab. de Citogenetica Vegetal; Colaco, Waldeciro [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear. Lab. de Radioagronomia; Meunier, Isabelle [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Dept. de Engenharia Florestal; Camara, Terezinha R. [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Dept. de Quimica. Lab. de Cultura de Tecidos Vegetais

1999-12-01

 
 
 
 
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Anther, pollen and tapetum development in safflower, Carthamus tinctorius L.  

Science.gov (United States)

In safflower, the anther wall at maturity consists of a single epidermis, an endothecium, a middle layer and the tapetum. The tapetum consists mainly of a single layer of cells. However, this single-layer appearance is punctuated by loci having 'two-celled' groupings due to additional periclinal divisions in some tapetal cells. Meiotic division in microsporocytes gives rise to tetrads of microspores. The primexine is formed around the protoplasts of microspores while they are still enveloped within the callose wall. Just prior to microgametogenesis, the microspores enlarge through the process of vacuolation, and the exine wall pattern becomes established. Microgametogenesis results in the formation of 3-celled pollen grains. The two elongated sperm cells appear to be connected. The exine wall is highly sculptured with a distinct tectum, columellae, a foot layer, an endexine and a thin intine. Similar to other members of the Asteraceae family, the tapetum is of the invasive type. The most novel finding of this study is that in addition to the presence of invasive tapetal cells, a small population of 'non-invasive' tapetal cells is also present. The tapetal cells next to the anther locules in direct contact with the microspores become invasive and start to grow into the space between developing microspores. These tapetal cells synthesize tryphine and eventually degenerate at the time of gametogenesis releasing their content into the anther locules. A smaller population of non-invasive tapetal cells is formed as a result of periclinal divisions at the time of tapetum differentiation. These cells are not exposed to the anther locules until the degeneration of the invasive tapetal cells. The non-invasive tapetal cells have a different cell fate as they synthesize pollenkitt. This material is responsible for allowing some pollen grains to adhere to each other and to the anther wall after anther dehiscence. This observation explains the out-crossing ability of Carthamus species and varieties in nature. PMID:21573927

Yeung, Edward C; Oinam, Gunamani S; Yeung, Stephanie S; Harry, Indra

2011-12-01

62

Effect of Genotype and Callus Induction Medium on Green Plant Regeneration from Anther of Nepalese Rice Cultivars  

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Full Text Available Effects of genotype and medium composition on the frequency of callus induction and green plant regeneration from anther of Nepalese rice were investigated. Cold pretreated anthers from six rice genotypes at 8±2°C for seven days were cultured on three different callus induction media designated as Callus Induction Medium (CIM 1: N6 mineral salts + N6 vitamins (2 mg L-1 each + myoinositol (100 mg L-1 + 2,4-D (2.5 mg L-1 + KI (0.5 mg L-1 + AgNO3 (10 mg L-1 + maltose (50 g L-1, CIM 2: N6 mineral salts + MS organic salts + NAA (4 mg L-1 + Kinetin (KI (2 mg L-1 + Silver nitrate (AgNO3 (5 mg L-1 and sucrose 60 (g L-1 and CIM 3: CIM 2 without AgNO3.. The callus induction frequency was significantly affected by rice genotypes and genotype x medium interactions. The efficiency of callus induction (calli/anther was higher in CIM 1 (14.1% followed by CIM 2 (12.54% and CIM 3 (10.3%. CIM 2 was found to be superior for the recovery of green plants. Among genotypes, only the calli from Chandanath -3 and Khumal-4 were able to differentiate into green plants. In this study the calli induced on medium containing 2, 4-Dichloroacetic acid (2, 4-D had lower regeneration ability than the medium supplied with ?-naptthalene acetic acid (NAA. This study also revealed that the temperate cultivars (hill rice were more responsive to anther culture than the tropical ones (terai rice.

R.K. Niroula

2009-01-01

63

Cross Section Through the Dehisced Anther of Xylopia collina  

Science.gov (United States)

Cross section through the dehisced anther of Xylopia collina of the pawpaw family (Annonaceae). Species of the genus Xylopia, as well as other members of this family, produce large pollen that is shed in units of four or sometimes even 32 grains (some tetrads visible in illustration). Associated with these compound pollen units in most genera are layers of sterile tissue, called septa, that separate the grains into chambers within each anther. Tsou and Johnson investigated the variation and development of the septa of Annonaceae, and found that despite variability in appearance, the septal tissues of all species were formed by the same developmental pathway. They propose that these tissues may have evolved in Annonaceae in response to a requirement for extra nutrients and support tissues for large pollen units.

Chih-Hua Tsou (Institute of Botany;Academia Sinica ADR;POSTAL)

2004-03-09

64

Ação do etileno em combinação com thidiazuron, nitrato de prata e ácido acetilsalicílico na cultura de anteras de pimentão Ethylene action in combination with Thidiazuron (TDZ, silver nitrate (AgNO3 and acetylsalicylic acid on sweet pepper anther culture  

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Full Text Available Verificou-se o efeito do etileno em combinação com o thidiazuron (TDZ, nitrato de prata (AgNO3 e ácido acetilsalicílico (AAS, na indução e regeneração de embriões em anteras de pimentão, genótipos F1 (PIX21C12#35 x Agronômico 08, (PIX21C04#4 x Linha 004, (PIX22C#31 x Linha 004, (PIX21C15#45 x Ikeda e (PIX22C#21 x Ikeda. Os botões foram coletados quando sépalas e pétalas tinham tamanhos aproximadamente iguais, correspondendo ao estádio de anteras com micrósporos uninucleados. As anteras foram inoculadas em placa de Petri contendo meio de cultura C adicionado de 4,5 mM de TDZ; meio C acrescido de 0,05 mM de 2,4-D, 0,05 mM de cinetina e 88,8 mM de AAS; meio C acrescido de 0,05 mM de 2,4-D, 0,05 mM de cinetina e 5,0 mg/L de AgNO3. Em seguida, foram colocadas em ambiente escuro a 35ºC durante oito dias e enriquecido com ethephon, por 0; 2; 4; 6 ou 8 dias num esquema fatorial com quatro repetições, sendo cada placa considerada uma parcela contendo 20 a 24 anteras.O período de permanência de quatro dias, em ambiente enriquecido com ethephon, e os meios com TDZ e AgNO3, foram os mais favoráveis à indução de anteras. O TDZ também promoveu maior indução de calos embriogênicos. As maiores taxas de necrose ocorreram no meio com AAS. Só ocorreu regeneração direta em plântulas no meio C acrescido de 5 mg/L de AgNO3, sendo oito dias o melhor período. Os genótipos mais responsivos foram PIX22C#31 x linha 004 e PIX22C#21 x Ikeda. Observou-se a formação de plântulas haplóides e diplóides mediante análise da ponta de raíz. Considerando-se que a regeneração foi direta, sem passar por calos, supõe-se que as plântulas diplóides obtidas sejam provenientes dos micrósporos, devendo portanto ter ocorrido uma diploidização in vitro.The influence of ethylene used in combination with Thidiazuron (TDZ, silver nitrate (AgNO3 and acetylsalicylic acid (ASA was evaluated on sweet pepper androgenesis of F1 genotypes (PIX21C12#35 x Agronômico 08, PIX21C04#4 x Line 004, PIX22C#31 x Line 004, PIX21C15#45 x Ikeda and PIX22C#21 x Ikeda. Floral buds were collected when sepals and petals were approximately of equal size, corresponding to the uninucleated stage of microspores. Anthers were placed in Petri dishes containing three mediums: C medium supplemented with TDZ (4.5mM; C medium plus 2,4-D (0,05mM, Kinetin (0.5mM and ASA (88,8mM or AgNO3 (5.0 mg/L. After inoculation, the anthers were kept in the environment with ethephon for 0, 2, 4, 6 or 8 days at 35ºC for eight days in the dark. The experiment was conducted in a factorial design with four replications. Each replicate consisted of one Petri dish containing 20-24 anthers. TDZ and AgNO3 were most effective for inducing somatic embryos after four days with Ethrel. The greatest rates of necrosis took place on the medium with AAS. Direct regeneration of plantlets occurred only on medium supplemented with 5 mg/L of AgNO3 after an eight-day treatment with Ethrel. The most responsive genotypes were PIX22C#31 x Line 004 and PIX22C#21 x Ikeda. Chromosome number of the seedlings was verified through the root tip analysis which indicated the presence of haploid and diploid chromosome number. Since regeneration was direct, ie without going through callus phase, it is hypothesized that the diploid seedlings came from in vitro diploidization.

José Magno Q. Luz

1999-11-01

65

Improved Androgenesis of Broccoli (Brassica oleracea var italica Anthers Using Sucrose and Growth Regulators  

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Full Text Available The presented study was conducted to study the effects of BAP and its combinations with 2, 4-D and sucrose concentrations on androgenesis of broccoli cv. ‘Arcadia’. The MS Basel media supplemented with AC (0.5 g L-1 and 3% sucrose was used. The experiment was laid out in Completely Randomized Design (CRD using 3 replicates. The effects of BAP in combination with 2, 4-D and sucrose concentrations on androgenesis of broccoli (cv Arcadia anther cultures were investigated. The MS basal media supplemented with activated charcoal (AC (0.5 g L-1 was used. The medium complemented with BAP (1 mg L-1 plus 2, 4-D (0.5 mg L-1 significantly increased the percentage of anthers developing embryos (90%. Increasing 2, 4-D concentration (1 mg L-1 significantly decreased the percentage of anthers formed embryos (10%. Regarding the regeneration of the formed embryos, the culture medium containing BAP (1 mg L-1+2, 4-D (0.5 mg L-1 or BAP (1 mg L-1+2, 4-D (1 mg L-1 produced the high percentages of embryos induced callus. The maximum percentage of embryos developed into plantlets were obtained with culture medium with BAP (1 mg L-1+2, 4-D (0.5 mg L-1 followed by BAP (1 mg L-1 and 2, 4-D (1 mg L-1. Concerning sucrose concentration, the culture medium with low sucrose concentration (20 g L-1 enhanced the percentage of anthers developed embryos. The higher sucrose concentrations (50 and 60 g L-1 increased percentages of dead anthers and anthers formed callus and decreased the percentage of embryos developing plantlets. BAP in combinations with 2, 4-D and low concentrations of sucrose can be successfully used to perform embryos and/or callus from the callus induction and embryos development either to callus or plants.

Magdi A.A. Mousa

2014-01-01

66

Confronting the Marginalization of Culturally Responsive Pedagogy  

Science.gov (United States)

Globally, over the last two decades, attention to culturally responsive, multicultural approaches to teaching have largely been supplanted by standardized curricula and pedagogy that derive from neoliberal business models of school reform. In this essay, I discuss three factors that contribute to the marginalization of culturally responsive

Sleeter, Christine E.

2012-01-01

67

Culturally Responsive Leadership in School Libraries  

Science.gov (United States)

Students need culturally responsive teacher-librarians who focus on 21st century skills for all students. Basic principles for culturally responsive leadership in school libraries are articulated by multicultural educators who know that social equity is more important than ever, as the number of diverse and underserved students increase each year.…

Summers, Laura L.

2010-01-01

68

Effects of Culture and Response Format on Extreme Response Style.  

Science.gov (United States)

Examines the question of whether cultural and ethnic groups differ in their extreme response style. Studies questionnaire responses of Hispanic and non-Hispanic male Navy recruits and suggests that differences in extreme response style may be attributable to differences in judgment style across the two cultural groups. (MW)

Hui, C. Harry; Triandis, Harry C.

1989-01-01

69

In Vitro ANTHER CULTURE OF RICE HYBRIDS  

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Full Text Available En el Laboratorio de Mejoramiento de Arroz y Maíz del CIFA "Las Torres", en Sevilla, España, auspiciado por un proyecto de investigación, comenzó a desarrollarse un programa de obtención de variedades, que incluía en sus objetivos la utilización del cultivo de anteras de híbridos. Para ello se evaluaron diferentes medios para la formación de callos y regeneración de plantas verdes así como anteras de híbridos F1, provenientes de 15 cruzamientos. Los resultados mostraron que los más altos porcentajes de callos y plantas verdes como proceso continuo fueron obtenidos con los medios N6m y MS respectivamente. La mejor respuesta a la formación de callos fue obtenida por el cruce Puntal/Thaibonnet y regeneración de plantas verdes Doñana/V7876 y Lemont/Newbonnet.

Noraida Pu00E9rez

2003-01-01

70

Determination of Suitable Microspore Stage and Callus Induction from Anthers of Kenaf (Hibiscus cannabinus L.)  

Science.gov (United States)

Kenaf (Hibiscus cannabinus L.) is one of the important species of Hibiscus cultivated for fiber. Availability of homozygous parent lines is prerequisite to the use of the heterosis effect reproducible in hybrid breeding. The production of haploid plants by anther culture followed by chromosome doubling can be achieved in short period compared with inbred lines by conventional method that requires self pollination of parent material. In this research, the effects of the microspore developmental stage, time of flower collection, various pretreatments, different combinations of hormones, and culture condition on anther culture of KB6 variety of Kenaf were studied. Young flower buds with immature anthers at the appropriate stage of microspore development were sterilized and the anthers were carefully dissected from the flower buds and subjected to various pretreatments and different combinations of hormones like NAA, 2,4-D, Kinetin, BAP, and TDZ to induce callus. The best microspore development stage of the flower buds was about 6–8?mm long collected 1-2 weeks after flower initiation. At that stage, the microspores were at the uninucleate stage which was suitable for culture. The best callus induction frequency was 90% in the optimized semisolid MS medium fortified with 3.0?mg/L BAP + 3.0?mg/L NAA.

Binti Kayat, Fatimah; Ermiena Surya Mat Hussin, Zeti; Susanto, Dwi; Ariffulah, Mohammed

2014-01-01

71

Culture and Crisis Response in New Zealand  

Science.gov (United States)

New Zealand is a bicultural nation, founded on the signing of the Treaty of Waitangi by the native Maori and the British Crown. It is also home to people from many countries, cultures and ethnicities. Therefore, culturally-relevant response to crisis events has become a significant aspect of the Ministry of Education's interdisciplinary Traumatic…

Annan, Jean; Dean, Shelley; Henry, Geoff; McGhie, Desiree; Phillipson, Roger

2010-01-01

72

Corporate cultural responsibility - the cultural commitment of Austrian companies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

"Corporate Cultural Responsibility bezeichnet das kulturelle Engagement von Unternehmen, wie den Aufbau von Kunstsammlungen, Kulturvermittlung für die MitarbeiterInnen, Kunst- und Kultursponsoring sowie Mäzenatentum. Im Rahmen dieses Artikels werden die Ergebnisse einer Erhebung zum kulturellen Engagement von neun österreichischen Unternehmen dargestellt. Es werden die Formen und Instrumente des Engagements, die Motive und Zielgruppen erläutert. Die Untersuchung zeigt auf, dass die Un...

2007-01-01

73

Toward a More Culturally Responsive General Music Classroom  

Science.gov (United States)

This article seeks to characterize culturally responsive teaching; consider how it differs from other pedagogical approaches in music education informed by culture, such as multicultural music education; and offer ideas for making the general music classroom more culturally responsive.

Abril, Carlos R.

2013-01-01

74

Culturally divergent responses to mortality salience.  

Science.gov (United States)

Two experiments compared the effects of death thoughts, or mortality salience, on European and Asian Americans. Research on terror management theory has demonstrated that in Western cultural groups, individuals typically employ self-protective strategies in the face of death-related thoughts. Given fundamental East-West differences in self-construal (i.e., the independent vs. interdependent self), we predicted that members of Eastern cultural groups would affirm other people, rather than defend and affirm the self, after encountering conditions of mortality salience. We primed European Americans and Asian Americans with either a death or a control prime and examined the effect of this manipulation on attitudes about a person who violates cultural norms (Study 1) and on attributions about the plight of an innocent victim (Study 2). Mortality salience promoted culturally divergent responses, leading European Americans to defend the self and Asian Americans to defend other people. PMID:21705518

Ma-Kellams, Christine; Blascovich, Jim

2011-08-01

75

An Agenda to Strengthen Culturally Responsive Pedagogy  

Science.gov (United States)

Over the last two decades in many countries, culturally responsive, multicultural and bilingual approaches to teaching have largely been replaced by standardised curricula and pedagogy, rooted in a political shift toward neoliberalism that has pushed business models of school reform. I argue that neoliberal reforms, by negating the central…

Sleeter, Christine E.

2011-01-01

76

Fine Division of Rice Anther Development by Cytological Morphology  

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A cytological and morphological study was conducted on the anther of a hybrid rice (Oryza Sativa L. indica) strain, Chuan You 9527. To sutdy the growth procedures of pollen and anther wall, their development processes from stamen primordia initiation to pollen maturation were observed and divided into stages. Rice spikelets ranging from approx. 1.0 millimeter to approx. 10.0 millimeter were chosen; loading films of anthers were prepared by using the techniques of paraffin section, and they we...

2011-01-01

77

Culturally Responsive Teaching: Theory, Research, and Practice. Multicultural Education Series.  

Science.gov (United States)

This volume makes the case for using culturally responsive teaching to improve the school performance of underachieving students of color. Key components of culturally responsive teaching are discussed. The chapters are: (1) "Challenges and Perspectives"; (2) "Power Pedagogy through Cultural Responsiveness"; (3) "The Power of Caring"; (4) "Culture

Gay, Geneva

78

Efeitos do estádio de desenvolvimento da antera e da radiação gama na formação de calos derivados de anteras de tomate Anther development stage and gamma radiation effects on tomato anther-derived callus formation  

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Full Text Available Este trabalho foi conduzido visando: (I determinar a influência do estádio de desenvolvimento de anteras de tomate sobre a formação de calos e (II analisar o efeito da radiação gama no cultivo in vitro de anteras. No primeiro experimento, anteras de híbridos de tomate IPA 5 x Rotam 4 (F1 foram cultivadas em três meios nutritivos. Apesar da formação de calos ter sido induzida em todos os estádios de desenvolvimento, variando de prófase I à micrósporo mononucleado, a freqüência de calos produzidos decresceu com o avanço do estádio de desenvolvimento e se apresentou de forma semelhante nos meios testados. Anteras contendo meiócitos em estádio de prófase I mostraram maior freqüência de formação de calos. Tanto o comprimento da antera quanto o do botão floral apresentaram correlação significativa com o estádio de desenvolvimento. No segundo experimento, sementes e botões florais dos híbridos IPA 5 x Rotam 4 (F2, IPA 6 x Rotam 4 (F2 e IPA 8 x 217.1 (F2 foram submetidos à radiação gama e suas anteras foram cultivadas em dois meios descritos por Gresshoff & Doy (1972, contendo 2,0 mg L-1 de ANA + 5,0 mg L-1 de cinetina e 2,0 mg L-1 de ANA + 1,0 mg L-1 de cinetina. Não foram constatadas diferenças significativas, no que se refere à formação de calos, para os genótipos e doses estudadas - 200 Gy, para sementes e 20 Gy, para botões florais.Two experiments were carried (I to determine tomato anther development stage influence on callus production; and (II to investigate gamma radiation effects on anther culture. In the first experiment, anthers of a tomato hybrid (IPA 5 x Rotam 4 - F1 were grown on three media. Although calli were induced at all stages of anther development, varying from prophase I to mononucleate microspore, callus frequency decreased as anther development progressed and calli induction were not significantly affected by all media tested. Anthers containing prophase I meiocytes produced the highest calli frequency. Anther and flower bud length both were significantly correlated with anther development stage. In the second experiment, seeds and floral buds of tomato hybrids IPA 5 x Rotam 4 (F2, IPA 6 x Rotam 4 (F2 and IPA 8 x 217.1 (F2 were submitted to gamma-ray and anthers were plated on two media described by Gresshoff & Doy (1972 supplemented with 2.0 mg L-1 NAA + 5.0 mg L-1 KIN and 2.0 mg L-1 NAA + 1.0 mg L-1 KIN. No significant differences for genotype and dosage tested were found for calli formation.

Ana Christina R. Brasileiro

1999-10-01

79

Sugar and auxin signaling pathways respond to high-temperature stress during anther development as revealed by transcript profiling analysis in cotton.  

Science.gov (United States)

Male reproduction in flowering plants is highly sensitive to high temperature (HT). To investigate molecular mechanisms of the response of cotton (Gossypium hirsutum) anthers to HT, a relatively complete comparative transcriptome analysis was performed during anther development of cotton lines 84021 and H05 under normal temperature and HT conditions. In total, 4,599 differentially expressed genes were screened; the differentially expressed genes were mainly related to epigenetic modifications, carbohydrate metabolism, and plant hormone signaling. Detailed studies showed that the deficiency in S-adenosyl-L-homocysteine hydrolase1 and the inhibition of methyltransferases contributed to genome-wide hypomethylation in H05, and the increased expression of histone constitution genes contributed to DNA stability in 84021. Furthermore, HT induced the expression of casein kinasei (GhCKI) in H05, coupled with the suppression of starch synthase activity, decreases in glucose level during anther development, and increases in indole-3-acetic acid (IAA) level in late-stage anthers. The same changes also were observed in Arabidopsis (Arabidopsis thaliana) GhCKI overexpression lines. These results suggest that GhCKI, sugar, and auxin may be key regulators of the anther response to HT stress. Moreover, phytochrome-interacting factor genes (PIFs), which are involved in linking sugar and auxin and are regulated by sugar, might positively regulate IAA biosynthesis in the cotton anther response to HT. Additionally, exogenous IAA application revealed that high background IAA may be a disadvantage for late-stage cotton anthers during HT stress. Overall, the linking of HT, sugar, PIFs, and IAA, together with our previously reported data on GhCKI, may provide dynamic coordination of plant anther responses to HT stress. PMID:24481135

Min, Ling; Li, Yaoyao; Hu, Qin; Zhu, Longfu; Gao, Wenhui; Wu, Yuanlong; Ding, Yuanhao; Liu, Shiming; Yang, Xiyan; Zhang, Xianlong

2014-03-01

80

Organizational culture during the accident response process  

International Nuclear Information System (INIS)

The ability of an organization to effectively move from an anticipatory to an ad hoc strategy may well depend on the organization having the ability to balance these two apparently dichotomous cultural styles. The organization which is most capable of making the necessary transition in an optimal manner may well exhibit some aspects of both cultural styles during normal operations. Data collected at one NPP does exhibit this pattern of results, with the organization exhibiting a clear hierarchical chain of command and perceived conventional behavioral expectations as well as exhibiting a more decentralized and collegial approach to decisionmaking, a team work orientation, and informal communications. Thus, it is expected that this organization possesses the capabilities to make a successful transition from an anticipatory to an ad hoc strategy. Data collected at a second NPP more strongly exhibits the traditional style suggested as being important during the anticipatory strategy, with more formal communications and bureaucratically controlled decision-making. This organization may experience difficulty if faced with the need to make a transition from an anticipatory to an ad hoc strategy. These conclusions are further validated based on observation of Emergency Preparedness Exercise Inspections, which suggest that the more anticipatory types of behaviors actually inhibit successful performance during an ad hoc response. The final validation of these hypotheses needs to be demonstrated with cultural data collected during emergency simulations. The mechanism to obtain such data during these types of situations is an area for future research

1992-06-07

 
 
 
 
81

Callus induction and plant regeneration of tomato (Lycopersicon esculentum cv. IPA 5 via anther culture Indução de calos e regeneração de plantas a partir do cultivo in vitro de anteras de tomate (Lycopersicon esculentum cv. IPA 5  

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Full Text Available Different growth regulators combinations were tested on the production of anther callus in tomato cultivar IPA 5. Calli were induced on media supplemented with 1.0mgL-1 gibberellic acid (GA3, 0.05mgL-1 alpha-naphthaleneacetic acid (NAA plus 0.1mgL-1 6-benzylaminopurine (BAP, or with 1.0mgL-1 BAP plus 1.0mgL-1 NAA. The medium containing 1.0mgL-1 BAP and 1.0mgL-1 NAA produced the highest calli frequency, and promoted plant regeneration by indirect organogenesis, when calli were transferred to 0.01mgL-1 BAP and 0.001mgL-1 NAA. Plants regenerated presented tetraploid cells and rare diploid cells. These tetraploid plants could be used as source for further obtainment of trisomic lines, for the purpose of genic localization studies and protein compounds analysis.Diferentes combinações de reguladores de crescimento foram testadas na produção de calos a partir do cultivo de anteras de tomate cultivar IPA 5. Calos foram induzidos no meio suplementado com 1,0mgL-1 de ácido giberélico (GA3 + 0,05mgL-1 de alfa-ácido naftalenoacético (ANA + 0,1mgL-1 de 6-benzilaminopurina (BAP, ou com 1,0mgL-1 de BAP + 1,0mgL-1 de ANA. O meio contendo 1,0mgL-1 de BAP e 1,0mgL-1 de ANA produziu a maior freqüência de calos e promoveu a regeneração de plantas através de organogênese indireta, quando os calos foram transferidos para 0,01mgL-1 de BAP e 0,001mgL-1 de ANA. As plantas regeneradas apresentaram células tetraplóides e, raramente, células diplóides. Estas plantas tetraplóides podem servir como fonte para posterior obtenção de linhagens trissômicas, para serem utilizadas em estudos de localização gênica e em análises de compostos protéicos.

Ana Christina Rabello Brasileiro

1999-12-01

82

Developmental and heat stress-regulated expression of HsfA2 and small heat shock proteins in tomato anthers  

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The high sensitivity of male reproductive cells to high temperatures may be due to an inadequate heat stress response. The results of a comprehensive expression analysis of HsfA2 and Hsp17-CII, two important members of the heat stress system, in the developing anthers of a heat-tolerant tomato genotype are reported here. A transcriptional analysis at different developmental anther/pollen stages was performed using semi-quantitative and real-time PCR. The messengers were localized using in sit...

2010-01-01

83

Measurement of proliferative responses of cultured lymphocytes.  

Science.gov (United States)

Measurement of proliferative responses of human lymphocytes is a fundamental technique for the assessment of their biological responses to various stimuli. Most simply, this involves measurement of the number of cells present in a culture before and after the addition of a stimulating agent. This unit contains several different prototype protocols to induce proliferation in lymphocytes following exposure to mitogens, antigens, allogeneic or autologous cells, or soluble factors. Each of these protocols can be used in conjunction with an accompanying protocol, which contains methods to determine cell proliferation by incorporation of [(3)H]thymidine into DNA by nonradioactive methods, e.g., reduction of tetrazolium salts (MTT or WST-1). These protocols provide an estimate of cell proliferation indirectly by measuring DNA synthesis, and cell metabolic activity in an entire cell population, but no data on individual cells is obtained. A protocol for CFSE labeling allows direct detection of single proliferating cells and facilitates the quantification of cell divisions by flow cytometry according to the respective CFSE-dilution, and following costaining with fluorescent labeled antibodies, the characterization of subpopulations in the cell culture. PMID:21809319

Muul, Linda Mesler; Heine, Guido; Silvin, Christopher; James, Stephen P; Candotti, Fabio; Radbruch, Andreas; Worm, Margitta

2011-08-01

84

Morphological Study of the Versatile Anther Group in the Tribe Zingibereae (Zingiberaceae)  

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Scanning electron micrographs of anther development in Cautleya spicata (Sm.) Baker show that the appendages develop from the joint connective tissue where one end of the anther develops first, well before the other turns into the appendages. The anther with appendages is thus basifixed in a mature plant in Cautleya spicata while observation of Curcuma species reveals that the anther is dorsifixed, and the appendages are derived from the thecae of the anther. Mapping this characteristic of th...

Ngamriabsakul, Chatchai

2005-01-01

85

Pollen and Anther Development in Onobrychis schahuensis Bornm.(Fabaceae)  

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Young buds and flowers of Onobrychis schahuensis were removed at different stages of anther development and sectioned with micotome after preparation. The anther and pollen development were studied with light microscopy after staining. Results showed that some ultrastructural characters of anther and pollen grains were different from other Fabaceae members. The undifferentiated anther is ovoid-shaped and tetrasporangiated. The anther wall development follows the dicotyledonous ty...

Abdolkarim Chehregani; Nayereh Tanaomi; Massoud Ranjbar

2008-01-01

86

Morphological Study of the Versatile Anther Group in the Tribe Zingibereae (Zingiberaceae  

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Full Text Available Scanning electron micrographs of anther development in Cautleya spicata (Sm. Baker show that the appendages develop from the joint connective tissue where one end of the anther develops first, well before the other turns into the appendages. The anther with appendages is thus basifixed in a mature plant in Cautleya spicata while observation of Curcuma species reveals that the anther is dorsifixed, and the appendages are derived from the thecae of the anther. Mapping this characteristic of the anther in the six genera that possess versatile anther in Zingiberaceae, namely Camptandra, Cautleya, Curcuma, Laosanthus, Paracautleya and Roscoea, onto the molecular based phylogeny of the tribe suggests that the dorsifixed versatile anther of the Curcuma complex has been lost independently in Hitchenia, Smithatris and Stahlianthus, while the basifixed versatile anther has arisen independently in Camptandra and Cautleya/Roscoea.

Chatchai NGAMRIABSAKUL

2005-01-01

87

Haplodiploid androgenetic breeding in oat: genotypic variation in anther size and microspore development stage Melhoramento por haplodiploidização androgenética: variação genotípica no tamanho das anteras e no estágio de desenvolvimento dos micrósporos em aveia  

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Full Text Available Oat (Avena spp. is poorly responsive to the haplodiploidization process, which leads to the production of homozygous lines in one step, increasing breeding efficiency. Androgenetic haploids in small grain cereal crops are obtained from microspores cultured at the mononucleate stage, which can be identified by the size of anthers. In order to identify the appropriate anther size for in vitro culture, microspore cytological analyses were made in Avena sativa cultivars UPF 7, UPF 18, UFRGS 14, Stout and Avena sterilis CAV 3361, cultivated in growth chamber under controlled light and temperature conditions. Variation was observed within and among genotypes for anther size at each microspore developmental stage and according to the position of spikelets in the panicle. Architecture variation in panicle shape and non-linear microsporogenesis maturation increased the challenge of identifying potentially androgenetic oat anthers. Cytological screening before culture is critical in identifying microspores at the right stage for oat androgenesis.A aveia (Avena spp. tem sido pouco responsiva à haplodiploidização, um processo que aumenta a eficiência da seleção no melhoramento por gerar, em uma etapa, linhas puras homozigóticas. A fase mononucleada do micrósporo é critica para o sucesso da androgênese in vitro nos cereais de inverno e, em geral, pode ser inferida pelo tamanho da antera. Foram medidas anteras e analisados citológicamente micrósporos das cultivares de Avena sativa UPF 7, UPF 18, UFRGS 14, Stout e da linhagem CAV 3361 de Avena sterilis, cultivadas em câmaras de crescimento sob temperaturas dia-noite variando de 16ºC a 9ºC e 12 horas de intensidade luminosa de 300 mol m-2 s-1. O tamanho das anteras em cada fase de desenvolvimento dos micrósporos variou significativamente entre genótipos e de acordo com a região de inserção das espiguetas na panícula. A variação na arquitetura da panícula e a maturação não linear das espiguetas aumentam as dificuldades para a identificação das anteras potencialmente androgenéticas e podem explicar, em parte, os baixos resultados da androgênese na aveia. Os dados mostram a necessidade de uma análise citológica prévia para auxiliar a determinar a fase ideal de desenvolvimento dos micrósporos potencialmente responsivos à cultura de anteras, para o uso da androgenese na aveia.

Taniela De Cesaro

2009-02-01

88

Haplodiploid androgenetic breeding in oat: genotypic variation in anther size and microspore development stage / Melhoramento por haplodiploidização androgenética: variação genotípica no tamanho das anteras e no estágio de desenvolvimento dos micrósporos em aveia  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A aveia (Avena spp.) tem sido pouco responsiva à haplodiploidização, um processo que aumenta a eficiência da seleção no melhoramento por gerar, em uma etapa, linhas puras homozigóticas. A fase mononucleada do micrósporo é critica para o sucesso da androgênese in vitro nos cereais de inverno e, em ge [...] ral, pode ser inferida pelo tamanho da antera. Foram medidas anteras e analisados citológicamente micrósporos das cultivares de Avena sativa UPF 7, UPF 18, UFRGS 14, Stout e da linhagem CAV 3361 de Avena sterilis, cultivadas em câmaras de crescimento sob temperaturas dia-noite variando de 16ºC a 9ºC e 12 horas de intensidade luminosa de 300 mol m-2 s-1. O tamanho das anteras em cada fase de desenvolvimento dos micrósporos variou significativamente entre genótipos e de acordo com a região de inserção das espiguetas na panícula. A variação na arquitetura da panícula e a maturação não linear das espiguetas aumentam as dificuldades para a identificação das anteras potencialmente androgenéticas e podem explicar, em parte, os baixos resultados da androgênese na aveia. Os dados mostram a necessidade de uma análise citológica prévia para auxiliar a determinar a fase ideal de desenvolvimento dos micrósporos potencialmente responsivos à cultura de anteras, para o uso da androgenese na aveia. Abstract in english Oat (Avena spp.) is poorly responsive to the haplodiploidization process, which leads to the production of homozygous lines in one step, increasing breeding efficiency. Androgenetic haploids in small grain cereal crops are obtained from microspores cultured at the mononucleate stage, which can be id [...] entified by the size of anthers. In order to identify the appropriate anther size for in vitro culture, microspore cytological analyses were made in Avena sativa cultivars UPF 7, UPF 18, UFRGS 14, Stout and Avena sterilis CAV 3361, cultivated in growth chamber under controlled light and temperature conditions. Variation was observed within and among genotypes for anther size at each microspore developmental stage and according to the position of spikelets in the panicle. Architecture variation in panicle shape and non-linear microsporogenesis maturation increased the challenge of identifying potentially androgenetic oat anthers. Cytological screening before culture is critical in identifying microspores at the right stage for oat androgenesis.

Cesaro, Taniela De; Baggio, Maria Irene; Zanetti, Silvia Andréia; Suzin, Marilei; Augustin, Lizete; Brammer, Sandra Patussi; Iorczeski, Edson Jair; Milach, Sandra Cristina Kothe.

89

Culturally Responsive: Art Education in a Global Era  

Science.gov (United States)

Facing the era of globalization, culturally responsive art teachers must recognize that students' home culture, including local artistic expression, is inevitably influenced by global forces. They should strive to engage with students systems and issues of globalization and its impact on their community culture and art. In this article, the author…

Lai, Alice

2012-01-01

90

Efeitos do estádio de desenvolvimento da antera e da radiação gama na formação de calos derivados de anteras de tomate / Anther development stage and gamma radiation effects on tomato anther-derived callus formation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este trabalho foi conduzido visando: (I) determinar a influência do estádio de desenvolvimento de anteras de tomate sobre a formação de calos e (II) analisar o efeito da radiação gama no cultivo in vitro de anteras. No primeiro experimento, anteras de híbridos de tomate IPA 5 x Rotam 4 (F1) foram cu [...] ltivadas em três meios nutritivos. Apesar da formação de calos ter sido induzida em todos os estádios de desenvolvimento, variando de prófase I à micrósporo mononucleado, a freqüência de calos produzidos decresceu com o avanço do estádio de desenvolvimento e se apresentou de forma semelhante nos meios testados. Anteras contendo meiócitos em estádio de prófase I mostraram maior freqüência de formação de calos. Tanto o comprimento da antera quanto o do botão floral apresentaram correlação significativa com o estádio de desenvolvimento. No segundo experimento, sementes e botões florais dos híbridos IPA 5 x Rotam 4 (F2), IPA 6 x Rotam 4 (F2) e IPA 8 x 217.1 (F2) foram submetidos à radiação gama e suas anteras foram cultivadas em dois meios descritos por Gresshoff & Doy (1972), contendo 2,0 mg L-1 de ANA + 5,0 mg L-1 de cinetina e 2,0 mg L-1 de ANA + 1,0 mg L-1 de cinetina. Não foram constatadas diferenças significativas, no que se refere à formação de calos, para os genótipos e doses estudadas - 200 Gy, para sementes e 20 Gy, para botões florais. Abstract in english Two experiments were carried (I) to determine tomato anther development stage influence on callus production; and (II) to investigate gamma radiation effects on anther culture. In the first experiment, anthers of a tomato hybrid (IPA 5 x Rotam 4 - F1) were grown on three media. Although calli were i [...] nduced at all stages of anther development, varying from prophase I to mononucleate microspore, callus frequency decreased as anther development progressed and calli induction were not significantly affected by all media tested. Anthers containing prophase I meiocytes produced the highest calli frequency. Anther and flower bud length both were significantly correlated with anther development stage. In the second experiment, seeds and floral buds of tomato hybrids IPA 5 x Rotam 4 (F2), IPA 6 x Rotam 4 (F2) and IPA 8 x 217.1 (F2) were submitted to gamma-ray and anthers were plated on two media described by Gresshoff & Doy (1972) supplemented with 2.0 mg L-1 NAA + 5.0 mg L-1 KIN and 2.0 mg L-1 NAA + 1.0 mg L-1 KIN. No significant differences for genotype and dosage tested were found for calli formation.

Ana Christina R., Brasileiro; Lilia, Willadino; Marcelo, Guerra; Waldeciro, Colaço; Isabelle, Meunier; Terezinha R., Camara.

91

Anther smuts of Caryophyllaceae: molecular analyses reveal further new species.  

Science.gov (United States)

Recent collections of Microbotryum (Pucciniomycotina, Basidiomycota) specimens inhabiting anthers of different caryophyllaceous host plants were analysed using LM and electron microscopy, as well as molecular phylogenetic analyses using rDNA (ITS and LSU) sequences. The phylogenetic relationships of caryophyllaceous anther parasites are discussed. Three new species, Microbotryum adenopetalae, M. minuartiae, and M. silenes-acaulis, are described based on morphological, ecological, and molecular characteristics. New host plants are reported for Microbotryum dianthorum (Dianthus jacquemontii and Petrorhagia saxifraga) and M. lychnidis-dioicae (Cucubalus baccifer and Silene zawadskii). For Microbotryum violaceum, a neotype is selected. PMID:18951773

Lutz, Matthias; Piatek, Marcin; Kemler, Martin; Chlebicki, Andrzej; Oberwinkler, Franz

2008-11-01

92

Culturally Responsive Dance Pedagogy in the Primary Classroom  

Science.gov (United States)

Dance has an important place in multicultural education and the development of culturally responsive pedagogy. Through dance, children can explore and express their own and others' cultures and share their stories in ways other than the spoken and written word. This paper presents a case study concerning a professional development programme in…

Melchior, Elizabeth

2011-01-01

93

A milestone in the doubled haploid pathway of cassava: a milestone in the doubled haploid pathway of cassava (Manihot esculenta Crantz): cellular and molecular assessment of anther-derived structures.  

Science.gov (United States)

This study was aimed at inducing androgenesis in cultured anthers of cassava (Manihot esculenta Crantz) to develop a protocol for the production of doubled haploids. Microspore reprogramming was induced in cassava by cold or heat stress of anthers. Since the anthers contain both haploid microspores and diploid somatic cells, it was essential to verify the origin of anther-derived calli. The origin of anther-derived calli was assessed by morphological screening followed by histological analysis and flow cytometry (FCM). Additionally, simple sequence repeat (SSR) and amplified fragmented length polymorphism (AFLP) assays were used for the molecular identification of the microspore-derived calli. The study clearly demonstrated the feasibility of producing microspore-derived calli using heat- or cold-pretreated anthers. Histological studies revealed reprogramming of the developmental pathway of microspores by symmetrical division of the nucleus. Flow cytometry analysis revealed different ploidy level cell types including haploids, which confirmed their origin from the microspores. The SSR and AFLP marker assays independently confirmed the histological and FCM results of a haploid origin of the calli at the DNA level. The presence of multicellular microspores in the in vitro system indicated a switch of developmental program, which constitutes a crucial step in the design of protocols for the regeneration of microspore-derived embryos and plants. This is the first detailed report of calli, embryos, and abnormal shoots originated from the haploid cells in cassava, leading to the development of a protocol for the production of doubled haploid plants in cassava. PMID:24026343

Perera, P I P; Ordoñez, C A; Lopez-Lavalle, L A Becerra; Dedicova, B

2014-01-01

94

Expressed sequences tags of the anther smut fungus, Microbotryum violaceum, identify mating and pathogenicity genes  

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Abstract Background The basidiomycete fungus Microbotryum violaceum is responsible for the anther-smut disease in many plants of the Caryophyllaceae family and is a model in genetics and evolutionary biology. Infection is initiated by dikaryotic hyphae produced after the conjugation of two haploid sporidia of opposite mating type. This study describes M. violaceum ESTs corresponding to nuclear genes expressed during conjugation and early hyphal production.

Yockteng Roxana; Marthey Sylvain; Chiapello Hélène; Gendrault Annie; Hood Michael E; Rodolphe François; Devier Benjamin; Wincker Patrick; Dossat Carole; Giraud Tatiana

2007-01-01

95

Fine Division of Rice Anther Development by Cytological Morphology  

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Full Text Available A cytological and morphological study was conducted on the anther of a hybrid rice (Oryza Sativa L. indica strain, Chuan You 9527. To sutdy the growth procedures of pollen and anther wall, their development processes from stamen primordia initiation to pollen maturation were observed and divided into stages. Rice spikelets ranging from approx. 1.0 millimeter to approx. 10.0 millimeter were chosen; loading films of anthers were prepared by using the techniques of paraffin section, and they were observed and then photographed with digital camera system for optical microscopy (Nikon DS-Ril-U2. The results showed that the whole development process of anther could be divided into thirteen fine stages, based on the significant alterations in the morphological characteristics of cells and tissues. The thirteen stages are archesporial cell stage, bi-parietal stage, tri-parietal stage, pollen mother cell forming stage (the above four stages together are known as microsporocyte forming stage, early pollen mother cell meiosis stage, mid pollen mother cell meiosis stage, pollen mother cell dayad stage, pollen mother cell tetrad stage( the above four stages are known collectively as microsporocyte meiosis stage, early microspore stage, mid microspore stage, late microspore stage, bi-cellular pollen stage, and mature pollen stage.

LI Gui-jie

2011-05-01

96

Early anther ablation triggers parthenocarpic fruit development in tomato.  

Science.gov (United States)

Fruit set and fruit development in tomato is largely affected by changes in environmental conditions, therefore autonomous fruit set independent of fertilization is a highly desirable trait in tomato. Here, we report the production and characterization of male-sterile transgenic plants that produce parthenocarpic fruits in two tomato cultivars (Micro-Tom and Moneymaker). We generated male-sterility using the cytotoxic gene barnase targeted to the anthers with the PsEND1 anther-specific promoter. The ovaries of these plants grew in the absence of fertilization producing seedless, parthenocarpic fruits. Early anther ablation is essential to trigger the developing of the transgenic ovaries into fruits, in the absence of the signals usually generated during pollination and fertilization. Ovaries are fully functional and can be manually pollinated to obtain seeds. The transgenic plants obtained in the commercial cultivar Moneymaker show that the parthenocarpic development of the fruit does not have negative consequences in fruit quality. Throughout metabolomic analyses of the tomato fruits, we have identified two elite lines which showed increased levels of several health promoting metabolites and volatile compounds. Thus, early anther ablation can be considered a useful tool to promote fruit set and to obtain seedless and good quality fruits in tomato plants. These plants are also useful parental lines to be used in hybrid breeding approaches. PMID:23581527

Medina, Mónica; Roque, Edelín; Pineda, Benito; Cañas, Luis; Rodriguez-Concepción, Manuel; Beltrán, José Pío; Gómez-Mena, Concepción

2013-08-01

97

Legal Response to the Destruction of Cultural, Religious and Historical  

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Full Text Available Now, certainly, we know that since ancient times, humans experience their own personal and work them into forms that our cultural, religious, historical know have reflected and also know that it works, and plays an important role in human social life. Cultural, historic and religious monuments in the definition shooting, said: Construction works and objects that are placed on them due to the relatively long time interest in history has a nation belongs to them, cultural, religious, historical, say. In this research, the legal response to the destruction of cultural, historic and religious studies, which have included the following cases: Part I: Defining cultural, religious, and historical examples of it, Part II: cultural, religious, and historical background, Part III: Cultural Heritage, Part IV: cultural, religious, historical association and dissociation with the heritage – religious, Part V: The ways of identifying cultural, religious, historical. So, must be said that the cultural, religious and historical heritage of the people who understand the law and the media to inform the public and appropriate legislation should be prevented from destroying them.

Amir Ahmadi

2013-01-01

98

Production of Haploid Tobacco Plants Using Anther Culture.  

Science.gov (United States)

Presents a tobacco haploid experiment in which students learn the cytogenetic technique of metaphase analysis of chromosomes and experience the basic principles of haploidy, diploidy, and polyploidy. (YDS)

Smith, Robert A.; Belzer, Norbert F.

2002-01-01

99

Desempenho de linhagens diaplóides de trigo obtidas via cultura de anteras quanto à tolerância ao alumínio, produção de grãos e altura de planta / Performance of dihaploid wheat lines obtained via anther culture in relation to the aluminum tolerance, grain yield and plant height  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Avaliaram-se 18 linhagens diaplóides de trigo, obtidas via cultura de anteras in vitro oriundas de híbridos F1, e dois cultivares IAC-24 e IAC-289, nos anos de 1999 e 2000, em dois locais do Estado de São Paulo: Capão Bonito (solo ácido, sem aplicação de calcário e em condição de sequeiro) e em Tatu [...] í (solo ácido, com aplicação de calcário e em condição de irrigação por aspersão). Em cada experimento avaliaram-se a produção de grãos e a altura das plantas. Foi, também, avaliada a tolerância à toxicidade de alumínio, empregando-se soluções nutritivas contendo 0, 2, 4, 6, 8 e 10 mg.L-1, em condição de laboratório. As linhagens diaplóides consideradas mostraram grande variabilidade para os caracteres agronômicos avaliados. Destacaram-se quanto à produção de grãos, considerando a média dos experimentos de Capão Bonito, as linhagens 9 (MRL"S"/BUC"S"//BUC"S"/3/ IAC-24), 4 (PF70402/ALD"S"//PAT72160/ALD"S" /3/PEW"S"/4/OPATA/5/IAC-60) e 3 (TEPOCA/IAC-24). Em Tatuí, considerando-se a média dos dois anos, destacaram-se quanto à produção de grãos as linhagens 4 e 5, oriundas do mesmo cruzamento. A linhagem 13 (JUN/GEN//IAC-24) apresentou as plantas mais baixas nos quatro experimentos. Todos os genótipos, com exceção da cultivar IAC-289 e da linhagem 13, foram considerados tolerantes a 10 mg.L-1 de Al3+, quando avaliados em soluções nutritivas. Os resultados reforçam a possibilidade de selecionar os genótipos tolerantes ao alumínio, em condição de laboratório, antes que sejam avaliados em campo, em solo ácido, tornando o processo de obtenção de linhagens tolerantes mais eficiente. Abstract in english Eighteen dihaploid wheat lines originated via anther culture from F1 hybrid plants and two cultivars IAC-24 and IAC-289 were evaluated in 1999 and 2000, at two locations of the State of São Paulo: Capão Bonito (acid soil without lime application and upland condition) and Tatuí (acid soil with lime a [...] pplication and sprinkler irrigation condition). In each trial the genotypes were evaluated for grain yield and plant height. Aluminum toxicity tolerance was also evaluated in the laboratory in nutrient solutions containing 0, 2, 4, 6, 8 and 10 mg.L-1 of aluminum. The evaluated dihaploid lines showed high variability for the considered agronomic characters. The lines 9 (MRL"S"/BUC"S"//BUC"S"/3/IAC-24), 4 (PF70402/ ALD"S"//PAT72160/ALD"S"/3/PEW"S"/4/OPATA/5/IAC-60) and 3 (TEPOCA/IAC-24) displayed good performance in relation to grain yield considering the means of the Capão Bonito trials. In Tatuí the lines 4 and 5 originated from the same cross showed good behaviour for grain yield taking into account the means of the trials. The line 13 (JUN/GEN//IAC-24) exhibited short plants in all trials. All genotypes, except the cultivar IAC-289 and the line 13 were considered tolerant at 10 mg.L-1 to Al3+, in nutrient solution. The results indicated the possibility to select tolerant genotypes to aluminum toxicity in laboratory condition before they are evaluated in acid soil, making the process of obtaining tolerant lines more efficient.

Marcus Vinicius, Salomon; Carlos Eduardo de Oliveira, Camargo; Antonio Wilson Penteado, Ferreira Filho; Armando, Pettinelli Júnior; Jairo Lopes de, Castro.

100

Expressed sequences tags of the anther smut fungus, Microbotryum violaceum, identify mating and pathogenicity genes  

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Full Text Available Abstract Background The basidiomycete fungus Microbotryum violaceum is responsible for the anther-smut disease in many plants of the Caryophyllaceae family and is a model in genetics and evolutionary biology. Infection is initiated by dikaryotic hyphae produced after the conjugation of two haploid sporidia of opposite mating type. This study describes M. violaceum ESTs corresponding to nuclear genes expressed during conjugation and early hyphal production. Results A normalized cDNA library generated 24,128 sequences, which were assembled into 7,765 unique genes; 25.2% of them displayed significant similarity to annotated proteins from other organisms, 74.3% a weak similarity to the same set of known proteins, and 0.5% were orphans. We identified putative pheromone receptors and genes that in other fungi are involved in the mating process. We also identified many sequences similar to genes known to be involved in pathogenicity in other fungi. The M. violaceum EST database, MICROBASE, is available on the Web and provides access to the sequences, assembled contigs, annotations and programs to compare similarities against MICROBASE. Conclusion This study provides a basis for cloning the mating type locus, for further investigation of pathogenicity genes in the anther smut fungi, and for comparative genomics.

Devier Benjamin

2007-08-01

 
 
 
 
101

Universities' Responses to Globalisation: The Influence of Organisational Culture  

Science.gov (United States)

This study sought to assess how and why some higher education institutions have responded to aspects of globalisation and, in particular how organisational culture influences universities' responses to globalisation. Using a predominantly qualitative, mixed-methods approach, empirical research was used to explore the impact of globalisation at…

Burnett, Sally-Ann; Huisman, Jeroen

2010-01-01

102

Culturally Responsive Teaching: When and How High School Teachers Should Cross Cultural Boundaries To Reach Students.  

Science.gov (United States)

In the 1980s several qualitative studies of midwestern public high schools that serve students of color were conducted. Many teachers attempted to reach these students by adopting culturally responsive teaching strategies. While some teachers insisted that abandoning traditional pedagogy was to give up on socially legitimate teaching, others tried…

Hemmings, Annette

103

Geoethics and geological culture: awareness, responsibility and challenges  

Directory of Open Access Journals (Sweden)

Full Text Available The international debate in the field of geoethics focuses on some of the most important environmental emergencies, while highlighting the great responsibilities of geoscientists, whatever field they work in, and the important social, cultural and economic repercussions that their choices can have on society. The GeoItalia 2009 and 2011 conferences that were held in Rimini and Turin, respectively, and were organized by the Italian Federation of Earth Science, were two important moments for the promotion of geoethics in Italy. They were devoted to the highlighting of how, and with what tools and contents, can the geosciences contribute to the cultural renewal of society. They also covered the active roles of geoscientists in the dissemination of scientific information, contributing in this way to the correct construction of social knowledge. Geology is culture, and as such it can help to dispel misconceptions and cultural stereotypes that concern natural phenomena, disasters, resources, and land management. Geological culture consists of methods, goals, values, history, ways of thinking about nature, and specific sensitivity for approaching problems and their solutions. So geology has to fix referenced values, as indispensable prerequisites for geoethics. Together, geological culture and geoethics can strengthen the bond that joins people to their territory, and can help to find solutions and answers to some important challenges in the coming years regarding natural risks, resources, and climate change. Starting from these considerations, we stress the importance of establishing an ethical criterion for Earth scientists, to focus attention on the issue of the responsibility of geoscientists, and the need to more clearly define their scientific identity and the value of their specificities.

Silvia Peppoloni

2012-07-01

104

The transformation of anthers in the msca1 mutant of maize.  

Science.gov (United States)

In normal anther development in maize (Zea mays L), large hypodermal cells in anther primordia undergo a series of proscribed cell divisions to form an anther containing microsporogenous cells and three distinctive anther wall layers: the tapetum, the middle layer and the endothecium. In homozygous msca1 mutants of maize, stamen primordia are initiated normally and large hypodermal cells can be detected in developing anthers. However, the normal series of cell division and differentiation events does not occur in msca1 mutant plants. Rather, structures containing parenchymal cells and ectopic, nonfunctional vascular strands are formed. The epidermal surfaces of these structures contain stomata, which are normally absent in maize anthers. Thus, all of the cell layers of the "anther" have been transformed in mutant plants. The filaments of the mutant structures are normal, and all other flower parts are normal. The msca1 mutation does not affect female fertility, but transformed "stamen" structures remain associated with mature ovules rather than aborting as in normal ear development. The msca1 mutation is distinctive in that only one part of a single (male) reproductive organ is transformed. The resulting structure has general vegetative features, but cannot be conclusively identified as a particular vegetative organ. PMID:12624765

Chaubal, Raj; Anderson, John R; Trimnell, Mary R; Fox, Tim W; Albertsen, Marc C; Bedinger, Patricia

2003-03-01

105

Differentiation of cultured epithelial cells: Response to toxic agents  

Energy Technology Data Exchange (ETDEWEB)

Cell culture systems are instrumental in elucidating regulation of normal function and mechanisms of its perturbation by toxic substances. To this end, three applications of epithelial cells cultured with 3T3 feeder layer support are described. First, treatment of the premalignant human epidermal keratinocyte line SCC-12F2 with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate suppressed cell growth and differentiation. This agent produced a biphasic growth response greatly inhibiting cell growth at 1 to 10 nM, but much less above 100 nM. Expression of the differentiated functions involucrin and transglutaminase was found to be inhibited markedly at concentrations above 10 nM. Second, 3-methylcholanthrene toxicity was surveyed in a variety of rat epithelial cell types. The two most sensitive to growth inhibition were epidermal and mammary epithelial cells, while those from bladder, prostate, thyroid, and endometrium were insensitive to growth inhibition. Finally, expression of estrogen receptors in rat endometrial cells was shown to be stimulated by the cAmP-elevating agent forskolin. Maximal stimulation of 3- to 6-fold occurred in 6 hr, compatible with a requirement for protein synthesis. Pursuit of such results will aid in understanding differences in response among cell types and species, in elucidating mechanisms of action of known toxic substances and, ultimately, in predicting toxicity of less well understood agents.

Rice, R.H.; LaMontagne, A.D.; Petito, C.T.; Rong, Xianhui (Charles A. Dana Laboratory of Toxicology, Boston, MA (USA))

1989-03-01

106

Research on cotton anther development of three male-sterile lines  

International Nuclear Information System (INIS)

Pollens of Sumian 22 were irradiated by 60Co ?-rays at a dose of 20Gy, then fertilized to pistil and harvested seed. Three male-sterile lines were selected from M1 plants, their anther observed by paraffin slice technique. Although there were some different characteristics during the abortion anther development, the abortion was consistent: the abortion stage from the development periods of pollen mother cells to microspore, pollen mother cells, tapetum, middle layer cells and the shape of anther were affected, the results contained micronucleus and double nucleus, cytoplasm expansion during the period of meiosis, tapetum and middle layer cells and so on were abnormal. (authors)

2009-12-01

107

Analysis of anther transcriptomes to identify genes contributing to meiosis and male gametophyte development in rice  

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Full Text Available Abstract Background In flowering plants, the anther is the site of male gametophyte development. Two major events in the development of the male germline are meiosis and the asymmetric division in the male gametophyte that gives rise to the vegetative and generative cells, and the following mitotic division in the generative cell that produces two sperm cells. Anther transcriptomes have been analyzed in many plant species at progressive stages of development by using microarray and sequence-by synthesis-technologies to identify genes that regulate anther development. Here we report a comprehensive analysis of rice anther transcriptomes at four distinct stages, focusing on identifying regulatory components that contribute to male meiosis and germline development. Further, these transcriptomes have been compared with the transcriptomes of 10 stages of rice vegetative and seed development to identify genes that express specifically during anther development. Results Transcriptome profiling of four stages of anther development in rice including pre-meiotic (PMA, meiotic (MA, anthers at single-celled (SCP and tri-nucleate pollen (TPA revealed about 22,000 genes expressing in at least one of the anther developmental stages, with the highest number in MA (18,090 and the lowest (15,465 in TPA. Comparison of these transcriptome profiles to an in-house generated microarray-based transcriptomics database comprising of 10 stages/tissues of vegetative as well as reproductive development in rice resulted in the identification of 1,000 genes specifically expressed in anther stages. From this sub-set, 453 genes were specific to TPA, while 78 and 184 genes were expressed specifically in MA and SCP, respectively. The expression pattern of selected genes has been validated using real time PCR and in situ hybridizations. Gene ontology and pathway analysis of stage-specific genes revealed that those encoding transcription factors and components of protein folding, sorting and degradation pathway genes dominated in MA, whereas in TPA, those coding for cell structure and signal transduction components were in abundance. Interestingly, about 50% of the genes with anther-specific expression have not been annotated so far. Conclusions Not only have we provided the transcriptome constituents of four landmark stages of anther development in rice but we have also identified genes that express exclusively in these stages. It is likely that many of these candidates may therefore contribute to specific aspects of anther and/or male gametophyte development in rice. In addition, the gene sets that have been produced will assist the plant reproductive community in building a deeper understanding of underlying regulatory networks and in selecting gene candidates for functional validation.

Sharma Rita

2011-05-01

108

Hemopoietic cell precursor responses to erythropoietin in plasma clot cultures  

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The time dependence of the response of mouse bone marrow cells to erythropoietin (Ep) in vitro was studied. Experiments include studies on the Ep response of marrow cells from normal, plethoric, or bled mice. Results with normal marrow reveal: (1) Not all erythroid precursors (CFU-E) are alike in their response to Ep. A significant number of the precursors develop to a mature erythroid colony after very short Ep exposures, but they account for only approx. 13% of the total colonies generated when Ep is active for 48 hrs. If Ep is active more than 6 hrs, a second population of erythroid colonies emerges at a nearly constant rate until the end of the culture. Full erythroid colony production requires prolonged exposure to erythropoietin. (2) The longer erythropoietin is actively present, the larger the number of erythroid colonies that reach 17 cells or more. Two distinct populations of immediate erythroid precursors are also present in marrow from plethoric mice. In these mice, total colony numbers are equal to or below those obtained from normal mice. However, the population of fast-responding CFU-E is consistently decreased to 10 to 20% of that found in normal marrow. The remaining colonies are formed from plethoric marrow at a rate equal to normal marrow. With increasing Ep exposures, the number of large colonies produced increases. From the marrow of bled mice, total erythroid colony production is equal to or above that of normal marrow. Two populations of colony-forming cells are again evident, with the fast-responding CFU-E being below normal levels. The lack of colonies from this group was compensated in bled mice by rapid colony production in the second population. A real increase in numbers of precursors present in this pool increased the rate of colony production in culture to twice that of normal marrow. The number of large colonies obtained from bled mice was again increased as the Ep exposure was lengthened. (ERB)

Kennedy, W.L.

1979-01-01

109

Calogênese in vitro em anteras de coffea arabica L. In vitro callogenesis in anthers of Coffea arabica L.  

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Full Text Available O café é um dos mais importantes produtos do mercado internacional; porém, o tempo gasto e os recursos despendidos são fatores limitantes para o melhoramento do cafeeiro por meio de métodos convencionais. Contudo, a cultura de anteras surge como uma alternativa viável e de curto prazo para solução desses problemas. Com o presente trabalho, objetivou-se a produção de dihaplóides com a cultura de anteras do cafeeiro (androgênese indireta, buscando um protocolo para a fase de indução de calos. Para tanto, foi efetuada a assepsia dos botões florais e das anteras, que, em seguida, foram inoculadas em meio IC e mantidas no escuro por 8 semanas, sob temperatura de 25ºC ± 1. Para induzir a calogênese em anteras da cv. Acaiá Cerrado, foram testadas as concentrações de 2,4-D (0, 1, 2 e 4 mg.L-1 x cinetina (0, 2, 4 e 8 mg.L-1 e 2,4-D (0; 0,5; 1 e 2 mg.L-1 x AIB (0; 0,5; 1 e 2 mg.L-1 mais 2iP (2 mg.L-1 e, para a cv. Rubi, as concentrações de 2,4-D (0, 1, 2 e 4 mg.L-1 x cinetina (0, 2, 4 e 8 mg.L-1. Foi observado que a maior porcentagem de indução de calogênese em anteras na cv. Acaiá Cerrado ocorre com as combinações de 2,4-D (2 mg.L-1 + cinetina (1,9 mg.L-1 e 2,4-D (0,86 mg.L-1 + AIB (1 mg.L-1+ 2iP (2 mg.L-1; para cv. Rubi, a combinação de 2,4-D (1,9 mg.L-1 e cinetina (4 mg.L-1.The coffee is one of the most important products of the international market, however the time and money wasted in breeding programs are limiting factors for its improvement. However, the anther culture appears as a viable alternative for a short time period solution for this problem. This work aimed to obtain the double haploids production from anther cultures of the coffee plant (indirect androgenesis aiming to optimize a protocol calluse induction. For this purpose, asseptic conditions of the flower budsand anthers were accomplished, folowed by inoculationin IC medium and the tissue were kept for eight weeks at 25ºC ± 1 in the dark. To induce callogenesis in anthers of the 'Acaiá Cerrado' there were tested 2,4-D (0, 1, 2 and 4 mg.L-1 x kinetin (0, 2, 4 and 8 mg.L-1 and 2,4-D (0; 0,5; 1 and 2mg.L-1 x AIB (0; 0,5; 1 and 2mg.-1 plus 2 iP (2 mg.L-1 concentrations and for the 'Rubi' 2,4-D (0, 1, 2 and 4 mg.L-1 x kinetin (0, 2, 4 and 8 mg.L-1 concentrations. It was observed that the highest percentage of callogenesis induction in anthers of the 'Acaiá Cerrado' was provenient from 2,4-D (2 mg.L-1 + kinetin (1,9 mg.L-1 and 2,4-D (0,86 mg.L-1 + AIB (1 mg.L-1+ 2iP (2mg.L-1 combinations for 'Rubi' 2,4-D (1,9 mg.L-1 and kinetin (4 mg.L-1.

Ednamar Gabriela Palú

2004-08-01

110

Antioxidant responses of rice seedling to Ce?+ under hydroponic cultures.  

Science.gov (United States)

Since the 1980s, rare earth elements have been commonly used in China because of their enriched fertilizers. To understand the potential benefits or damages of Ce(4+) on rice, the antioxidant responses (superoxide dismutase, ascorbate peroxidase, catalase activities, and ascorbate and glutathione contents) of rice seedling to Ce(4+) under hydroponic cultures were investigated. The results showed that Ce(4+) induced H(2)O(2) and O(2)(-) production of rice seedling. The inhibition studies with diphenylene iodonium suggested that the key enzyme responsible for oxidative bursts was primarily NADPH oxidase. Ce(4+) (0.02 mM) increased the antioxidant capacity of reduced ascorbate and glutathione and the levels of superoxide dismutase, ascorbate peroxidase, and catalase. However, antioxidant enzymes and antioxidant capacity of rice seedling were decreased by 0.2mM Ce(4+) treatment, indicating that higher content of Ce(4+) damaged the mechanism of defense responses and emerged the peroxidation of membrane lipids. These results will help us to understand the mechanism of Ce(4+) on rice and concern about its environmental impact in agriculture. PMID:21514673

Xu, Qiu-Man; Chen, Hong

2011-09-01

111

The response of human glioblastoma in culture to radiation  

International Nuclear Information System (INIS)

Cells from two human glioblastoma multiforme and one mouse glioma were grown in tissue cultures and their X-ray survival curve parameters were determined under oxygenated and hypoxic conditions. These were compared with the survival parameters for mouse fibroblasts (L5) and established cell lines from human carcinoma coli (HeLa S3) irradiated under identical conditions. There was no significant difference in response among the cell lines used. Repair of potentially lethal damage for human glioblastoma and HeLa S3 was assessed by the increase in survival which occurred as the cells were held in density inhibited stationary phase. The magnitude of repair of potentially lethal damage (slope modifying factors) for the glioblastoma and HeLa were 1.9 and 1.1, respectively. (author)

1980-01-01

112

Successful development of a shed-microspore culture protocol for doubled haploid production in Indonesian hot pepper (Capsicum annuum L.)  

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Various systems of anther and microspore cultures were studied to establish an efficient doubled haploid production method for Indonesian hot pepper (Capsicum annuum L.). A shed-microspore culture protocol was developed which outperformed all the previously reported methods of haploid production in pepper. The critical factors of the protocol are: selection of flower buds with more than 50% late unicellular microspores, a 1 day 4°C pretreatment of the buds, followed by culture of the anthers...

Supena, E. D. J.; Suharsono, S.; Jacobsen, E.; Custers, J. B. M.

2006-01-01

113

Radiation response of cultured human cells is unaffected by Johrei.  

Science.gov (United States)

Johrei has been credited with healing thousands from radiation wounds after the Hiroshima and Nagasaki bombs in 1945. This alternative medical therapy is becoming increasingly popular in the United States, as are other Energy Medicine modalities that purport to influence a universal healing energy. Human brain cells were cultured and exposed to increasing doses of ionizing radiation. Experienced Johrei practitioners directed healing intentionality toward the cells for 30 min from a distance of 20 cm and the fate of the cells was observed by computerized time-lapse microscopy. Cell death and cell divisions were tallied every 30 min before, during and after Johrei treatment for a total of 22.5 h. An equal number of control experiments were conducted in which cells were irradiated but did not receive Johrei treatment. Samples were assigned to treatment conditions randomly and data analysis was conducted in a blinded fashion. Radiation exposure decreased the rate of cell division (cell cycle arrest) in a dose-dependent manner. Division rates were estimated for each 30 min and averaged over 8 independent experiments (4 control and 4 with Johrei treatment) for each of 4 doses of X-rays (0, 2, 4 and 8 Gy). Because few cell deaths were observed, pooled data from the entire observation period were used to estimate death rates. Analysis of variance did not reveal any significant differences on division rate or death rate between treatment groups. Only radiation dose was statistically significant. We found no indication that the radiation response of cultured cells is affected by Johrei treatment. PMID:17549235

Hall, Zach; Luu, Tri; Moore, Dan; Yount, Garret

2007-06-01

114

The "Simmie" Side of Life: Old Order Amish Youths' Affective Response to Culturally Prescribed Deviance.  

Science.gov (United States)

Analyzed the counterintuitive affective response Old Order Amish youth make to unique cultural prescriptions for adolescent deviance (constructed by adult Amish culture). Interview data supported the basic principles of Terror Management Theory in an unexpected, indirect fashion. Rather than functioning as a specialized cultural-anxiety buffer…

Reiling, Denise M.

2002-01-01

115

Embryology of Swainsona formosa (Fabaceae: Anther and Ovule Development  

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Full Text Available Our study showed that floral morphology and anatomy in Swainsona formosa were typical of leguminous flower. The anthers were found to be tetrasporangiate, with a 3-layered wall below the epidermis. The wall was comprised of a layer of endothecium, middle layer and secretory tapetum. Pollen grains were triporate and shed at a two-cell stage. The ovules were campylotropous with a zigzag micropyle. Multiple embryo sacs were occasionally found but only one mature embryo was formed in the seed. Rubbing the receptive stigma with fingertip enhanced pollination, resulted in 100% pod formation on treated flowers. During fertilization, the pollen tube entered the embryo sac via one of two existing synergids, destroying the synergid in the process. The endosperm was of nuclear type, and only one or two layers of endosperm left as the seed reached its maturity. The seed coat was composed of a single layer of thick-walled palisade cells on the outside followed by a single layer hypodermal sclereids on the inside.

ZULKARNAIN

2005-03-01

116

"Because That's Who I Am": Extending Theories of Culturally Responsive Pedagogy to Consider Religious Identity, Belief, and Practice  

Science.gov (United States)

In this conceptual article the author explores the intersection of culturally responsive pedagogy and religious school contexts. He extends theories of culturally responsive pedagogy to consider how religion, a dimension of student culture that has largely been overlooked in the literature surrounding culturally responsive pedagogy, can inflect…

Dallavis, Christian

2011-01-01

117

Culturally Responsive Pedagogies in the Classroom: Indigenous Student Experiences across the Curriculum  

Science.gov (United States)

There is agreement that teaching practices should be responsive to the cultural identities of their students, but less clarity regarding both the specifics of culturally responsive pedagogies and effective strategies for implementing them in classrooms across the curriculum. A mixed-methods research approach evaluated the impact of teacher…

Savage, Catherine; Hindle, Rawiri; Meyer, Luanna H.; Hynds, Anne; Penetito, Wally; Sleeter, Christine E.

2011-01-01

118

Survey Response Styles, Acculturation, and Culture Among a Sample of Mexican American Adults  

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A number of studies have investigated use of extreme (ERS) and acquiescent (ARS) response styles across cultural groups. However, due to within-group heterogeneity, it is important to also examine use of response styles, acculturation, and endorsement of cultural variables at the individual level. This study explores relationships between acculturation, six Mexican cultural factors, ERS, and ARS among a sample of 288 Mexican American telephone survey respondents. Three aspects of acculturatio...

Davis, Rachel E.; Resnicow, Ken; Couper, Mick P.

2011-01-01

119

Biculturalization: Developing Culturally Responsive Approaches to Family Participation  

Science.gov (United States)

This manuscript describes a process for addressing cultural differences that is effective when applied specifically to collaborating with families in planning an intervention or an Individualized Education Program (IEP). The process, known as biculturalization, is designed to create culturally appropriate interventions by identifying and…

Sheehey, Patricia; Ornelles, Cecily; Noonan, Mary Jo

2009-01-01

120

[The ultrastructural observation of anthers of Chinese cabbage's mail-sterility].  

Science.gov (United States)

The fertile and sterile anthers of a Chinese cabbage (Brassica campestris L. ssp. chinensis Makino) were observed using electron microscope to find the ultrastructural feature of sterile anthers. The earliest abnormal phenomenon in sterile anther was nucleolus of sporogenous cells locating in the edge of nucleus. During microspore mother cell development, callus wall surrounding the cell displayed uneven in the thick ness and was discontinuous,and the some cytoplasm leaked out of the cell from some rifts in the wall. After meiosis of microspore mother cells, the cells of tetrad were irregular and some of them contained several nuclei. The exine of pollen began to be formed in tetrad in this cabbage. The evident disorder during exine formation in the sterile pollen occurred during its primexine formation and then the sporopollenin was irregularly deposited to form a layer of uneven and discontinuous pollen exine. Cytoplasm of aborting microspores contracted and finally degenerated after them released from tetrad. The tapetal cells of fertile anther began to synthesis abundant lipid material during microspore development. However, the tapetal cells of sterile anther did not synthesis lipid material during microspore aborting. The microspore abortion was first and tapetal degeneration second. Therefore, aborting microspore induced the functional default of tapetal cells synthesizing lipid material. The ultrastructural results on this study further complete and correct our previous results obtained by light microscope. PMID:16416967

Xie, Chao Tian; Yang, Yan Hong; Ge, Li Li; Wang, Rui; Tian, Hui Qiao

2005-12-01

 
 
 
 
121

Oviposition Attractancy of Bacterial Culture Filtrates: response of Culex quinquefasciatus  

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Oviposition attractants could be used for monitoring as well as controlling mosquitoes by attracting them to lay eggs at chosen sites. In the present study, culture filtrates of seven bacterial species were tested for their attractancy against gravid females of Culex quinquefasciatus. When their oviposition active indices (OAI) were studied, the culture filtrates of Bacillus cereus and Pseudomonas fluorescens exhibited oviposition attractancy (OAI = >0.3) at 100 ppm and the OAI were respectiv...

Poonam, S.; Kp, Paily; Balaraman, K.

2002-01-01

122

Transcriptomes and Proteomes Define Gene Expression Progression in Pre-meiotic Maize Anthers.  

Science.gov (United States)

Plants lack a germ line; consequently, during reproduction adult somatic cells within flowers must switch from mitotic proliferation to meiosis. In maize (Zea mays L.) anthers, hypoxic conditions in the developing tassel trigger pre-meiotic competence in the column of pluripotent progenitor cells in the center of anther lobes, and within 24 hr these newly specified germinal cells have patterned their surrounding neighbors to differentiate as the first somatic niche cells. Transcriptomes were analyzed by microarray hybridization in carefully staged whole anthers during initial specification events, after the separation of germinal and somatic lineages, during the subsequent rapid mitotic proliferation phase, and during final pre-meiotic germinal and somatic cell differentiation. Maize anthers exhibit a highly complex transcriptome constituting nearly three-quarters of annotated maize genes, and expression patterns are dynamic. Laser microdissection was applied to begin assigning transcripts to tissue and cell types and for comparison to transcriptomes of mutants defective in cell fate specification. Whole anther proteomes were analyzed at three developmental stages by mass spectrometric peptide sequencing using size-fractionated proteins to evaluate the timing of protein accumulation relative to transcript abundance. New insights include early and sustained expression of meiosis-associated genes (77.5% of well-annotated meiosis genes are constitutively active in 0.15 mm anthers), an extremely large change in transcript abundances and types a few days before meiosis (including a class of 1340 transcripts absent specifically at 0.4 mm), and the relative disparity between transcript abundance and protein abundance at any one developmental stage (based on 1303 protein-to-transcript comparisons). PMID:24939185

Zhang, Han; Egger, Rachel L; Kelliher, Timothy; Morrow, Darren; Fernandes, John; Nan, Guo-Ling; Walbot, Virginia

2014-01-01

123

Oviposition Attractancy of Bacterial Culture Filtrates: response of Culex quinquefasciatus  

Directory of Open Access Journals (Sweden)

Full Text Available Oviposition attractants could be used for monitoring as well as controlling mosquitoes by attracting them to lay eggs at chosen sites. In the present study, culture filtrates of seven bacterial species were tested for their attractancy against gravid females of Culex quinquefasciatus. When their oviposition active indices (OAI were studied, the culture filtrates of Bacillus cereus and Pseudomonas fluorescens exhibited oviposition attractancy (OAI = >0.3 at 100 ppm and the OAI were respectively 0.70 and 0.47. Culture filtrates of B. thuringiensis var. israelensis (wild type, B. t. var. israelensis (mutant and B. sphaericus showed attractancy at 2000 ppm with OAI of respectively 0.71, 0.59 and 0.68. However, the OAI of B. megaterium as well as Azospirillum brasilense was 0.13 (at 2000 ppm, which was less than 0.3 required to be considered them as attractants. When the oviposition attractancy of the bacterial culture filtrates were compared with that of a known oviposition attractant, p-cresol (at 10 ppm, the culture filtrates of B. t. var. israelensis (wild type and B. cereus were found to be more active than p-cresol, respectively with 64.2 and 54.3% oviposition.

S Poonam

2002-04-01

124

Oviposition Attractancy of Bacterial Culture Filtrates: response of Culex quinquefasciatus  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Oviposition attractants could be used for monitoring as well as controlling mosquitoes by attracting them to lay eggs at chosen sites. In the present study, culture filtrates of seven bacterial species were tested for their attractancy against gravid females of Culex quinquefasciatus. When their ovi [...] position active indices (OAI) were studied, the culture filtrates of Bacillus cereus and Pseudomonas fluorescens exhibited oviposition attractancy (OAI = >0.3) at 100 ppm and the OAI were respectively 0.70 and 0.47. Culture filtrates of B. thuringiensis var. israelensis (wild type), B. t. var. israelensis (mutant) and B. sphaericus showed attractancy at 2000 ppm with OAI of respectively 0.71, 0.59 and 0.68. However, the OAI of B. megaterium as well as Azospirillum brasilense was 0.13 (at 2000 ppm), which was less than 0.3 required to be considered them as attractants. When the oviposition attractancy of the bacterial culture filtrates were compared with that of a known oviposition attractant, p-cresol (at 10 ppm), the culture filtrates of B. t. var. israelensis (wild type) and B. cereus were found to be more active than p-cresol, respectively with 64.2 and 54.3% oviposition.

S, Poonam; KP, Paily; K, Balaraman.

125

Cultural responsiveness and social work practice: an Indian clinic's success.  

Science.gov (United States)

Social workers need to appreciate the traditions and beliefs of clients from different cultures to provide effective services. The success of one hospital clinic in serving American Indians in Boston demonstrates how this appreciation can be translated into programs that are relevant to a particular population or targeted group. PMID:3744167

Yukl, T

1986-01-01

126

30 Americans: An Inspiration for Culturally Responsive Teaching  

Science.gov (United States)

Art museums and other institutions of informal learning can promote multicultural understanding by collaborating with community ethnic groups and designing exhibitions that richly characterize the cultures they represent. Through the lens of educational programming for the exhibition "30 Americans," this article describes how both the Corcoran…

Powell, Linda S.

2012-01-01

127

Dynamic cultural modulation of neural responses to one's own and friend's faces  

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Long-term cultural experiences influence neural response to one's own and friend's faces. The present study investigated whether an individual's culturally specific pattern of neural activity to faces can be modulated by temporary access to other cultural frameworks using a self-construal priming paradigm. Event-related potentials were recorded from British and Chinese adults during judgments of orientations of one's own and friend's faces after they were primed with independent and interdepe...

Sui, Jie; Hong, Ying-yi; Hong Liu, Chang; Humphreys, Glyn W.; Han, Shihui

2013-01-01

128

Responsibility-sensitive fair compensation in different cultures  

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Recently many philosophers and social choice theorists have questioned traditional welfare egalitarianism by introducing a notion of responsibility. They propose to distinguish between two sets of individual characteristics: those for which individuals are to be kept responsible and those for which they can be compensated. This approach raises the related questions of where to draw the line between those two sets of characteristics and how to operationalise the notion of 'responsibility-sensi...

Schokkaert, Erik; Devooght, Kurt

1999-01-01

129

Radiation Response of Cultured Human Cells Is Unaffected by Johrei  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Johrei has been credited with healing thousands from radiation wounds after the Hiroshima and Nagasaki bombs in 1945. This alternative medical therapy is becoming increasingly popular in the United States, as are other Energy Medicine modalities that purport to influence a universal healing energy. Human brain cells were cultured and exposed to increasing doses of ionizing radiation. Experienced Johrei practitioners directed healing intentionality toward the cells for 30 min from a distance o...

Hall, Zach; Luu, Tri; Moore, Dan; Yount, Garret

2007-01-01

130

Examination of Meiosis Anomalies in Anthers of Vitis vinifera L. cv. Cavus  

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Meiotic anomalies in pollen mother cells in anthers of Vitis vinifera L. cv. Cavus (2n = 38) were examined by light microscopy. In most microspore mother cells, the course of meiosis is regular. In some cells irregularities were observed, including chromosome bridges, univalents and fragments. Microspore tetrads are isobilateral and tetrahedral.

Erol Kodak; Nurhan Buyukkartal, H.

2005-01-01

131

Response of Cellulase Activity in pH-Controlled Cultures of the Filamentous Fungus Acremonium cellulolyticus  

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Cellulase production was investigated in pH-controlled cultures of Acremonium cellulolyticus. The response to culture pH was investigated for three cellulolytic enzymes, carbomethyl cellulase (CMCase), avicelase, and ?-glucosidase. Avicelase and ?-glucosidase showed similar profiles, with maximum activity in cultures at pH 5.5–6. The CMCase activity was highest in a pH 4 culture. At an acidic pH, the ratios of CMCase and avicelase activity to cellulase activity defined by filter paper uni...

Prasetyo, Joni; Sumita, Shyuuhei; Okuda, Naoyuki; Park, Enoch Y.

2010-01-01

132

Efficient production of genetically engineered, male-sterile Arabidopsis thaliana using anther-specific promoters and genes derived from Brassica oleracea and B. rapa.  

Science.gov (United States)

Prevention of transgene flow from genetically modified crops to food crops and wild relatives is of concern in agricultural biotechnology. We used genes derived from food crops to produce complete male sterility as a strategy for gene confinement as well as to reduce the food purity concerns of consumers. Anther-specific promoters (A3, A6, A9, MS2, and MS5) were isolated from Brassica oleracea and B. rapa and fused to the beta-glucuronidase (GUS) reporter gene and candidate genes for male sterility, including the cysteine proteases BoCysP1 and BoCP3, and negative regulatory components of phytohormonal responses involved in male development. These constructs were then introduced into Arabidopsis thaliana. GUS analyses revealed that A3, A6, and A9 had tapetum-specific promoter activity from the anther meiocyte stage. Male sterility was confirmed in tested constructs with protease or gibberellin insensitive (gai) genes. In particular, constructs with BoCysP1 driven by the A3 or A9 promoter most efficiently produced plants with complete male sterility. The tapetum and middle layer cells of anthers expressing BoCysP1 were swollen and excessively vacuolated when observed in transverse section. This suggests that the ectopic expression of cysteine protease in the meiocyte stage may inhibit programmed cell death. The gai gene also induced male sterility, although at a low frequency. This is the first report to show that plant cysteine proteases and gai from food crops are available as a novel tool for the development of genetically engineered male-sterile plants. PMID:18758783

Konagaya, Ken-ichi; Ando, Sugihiro; Kamachi, Shinichiro; Tsuda, Mai; Tabei, Yutaka

2008-11-01

133

Stories that Matter: Native American Fifth Graders' Responses to Culturally Authentic Text  

Science.gov (United States)

The purpose of this study is to examine textual features in Native American children's literature and Native children's responses to these textual features. Culturally authentic children's literature was used to gain insights into children's perspectives as they engaged in responses within literature circles. This study utilized qualitative…

Hoffman, Angeline P.

2010-01-01

134

Digital Citizenship: Developing an Ethical and Responsible Online Culture  

Science.gov (United States)

Responsible and ethical use of the Internet is not something that teenagers, in particular, consider to be important, and serious consequences are beginning to emerge as a result of careless and offensive online behaviour. Teachers and teacher-librarians have a duty of care to make students aware of the potentially devastating effects of…

Oxley, Cathy

2010-01-01

135

Cytological Characterization and Allelism Testing of Anther Developmental Mutants Identified in a Screen of Maize Male Sterile Lines  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Proper regulation of anther differentiation is crucial for producing functional pollen, and defects in or absence of any anther cell type result in male sterility. To deepen understanding of processes required to establish premeiotic cell fate and differentiation of somatic support cell layers a cytological screen of maize male-sterile mutants has been conducted which yielded 42 new mutants including 22 mutants with premeiotic cytological defects (increasing this class fivefold), 7 mutants wi...

Timofejeva, Ljudmilla; Skibbe, David S.; Lee, Sidae; Golubovskaya, Inna; Wang, Rachel; Harper, Lisa; Walbot, Virginia; Cande, William Zacheus

2013-01-01

136

Probiotics in fish and shellfish culture: immunomodulatory and ecophysiological responses.  

Science.gov (United States)

Aquaculture is emerging as one of the most viable and promising enterprises for keeping pace with the surging need for animal protein, providing nutritional and food security to humans, particularly those residing in regions where livestock is relatively scarce. With every step toward intensification of aquaculture practices, there is an increase in the stress level in the animal as well as the environment. Hence, disease outbreak is being increasingly recognized as one of the most important constraints to aquaculture production in many countries, including India. Conventionally, the disease control in aquaculture has relied on the use of chemical compounds and antibiotics. The development of non-antibiotic and environmentally friendly agents is one of the key factors for health management in aquaculture. Consequently, with the emerging need for environmentally friendly aquaculture, the use of alternatives to antibiotic growth promoters in fish nutrition is now widely accepted. In recent years, probiotics have taken center stage and are being used as an unconventional approach that has numerous beneficial effects in fish and shellfish culture: improved activity of gastrointestinal microbiota and enhanced immune status, disease resistance, survival, feed utilization and growth performance. As natural products, probiotics have much potential to increase the efficiency and sustainability of aquaculture production. Therefore, comprehensive research to fully characterize the intestinal microbiota of prominent fish species, mechanisms of action of probiotics and their effects on the intestinal ecosystem, immunity, fish health and performance is reasonable. This review highlights the classifications and applications of probiotics in aquaculture. The review also summarizes the advancement and research highlights of the probiotic status and mode of action, which are of great significance from an ecofriendly, sustainable, intensive aquaculture point of view. PMID:24419543

C De, Bidhan; Meena, D K; Behera, B K; Das, Pronob; Das Mohapatra, P K; Sharma, A P

2014-06-01

137

Temperament trait of sensory processing sensitivity moderates cultural differences in neural response  

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This study focused on a possible temperament-by-culture interaction. Specifically, it explored whether a basic temperament/personality trait (sensory processing sensitivity; SPS), perhaps having a genetic component, might moderate a previously established cultural difference in neural responses when making context-dependent vs context-independent judgments of simple visual stimuli. SPS has been hypothesized to underlie what has been called inhibitedness or reactivity in infants, introversion ...

2010-01-01

138

Nonsteroidal anti-inflammatory drugs differentially affect the heat shock response in cultured spinal cord cells  

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Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to amplify the heat shock response in cell lines by increasing the binding of heat shock transcription factor–1 to heat shock elements within heat shock gene promoters. Because overexpression of the inducible heat shock protein 70 (Hsp70) was neuroprotective in a culture model of motor neuron disease, this study investigated whether NSAIDs induce Hsp70 and confer cytoprotection in motor neurons of dissociated spinal cord cultures...

Batulan, Zarah; Nalbantoglu, Josephine; Durham, Heather D.

2005-01-01

139

The molecular basis for uv response of cultured human cells  

Energy Technology Data Exchange (ETDEWEB)

During the past year we have analyzed the mechanism by which UV and H{sub 2}O{sub 2} increase the activity of AP-1 in HeLa cells. AP-1 is a dimeric protein complex composed of the fos and jun gene products. After UV irradiation of HeLa cells (or exposure to H{sub 2}O{sub 2}) expression of the c-jun gene rapidly increases at least 50-fold. This induction occurs through the previously identified AP-1 site in the c-jun promoter. This positive autoregulation is mediated by AP-1 complexes that are composed mostly of cJun. cJun is a phosphoprotein that undergoes complex changes in its phosphorylation state following exposure to phorbol esters, growth factors or transforming oncogenes. We show that UV irradiation causes increases in the phosphorylation of cJun. We have been trying to determine the common signal by which DNA damaging agents lead to activation of the UV response. We present evidence that oxidative stress may serve as a signal for AP-1 induction during the UV response. We are also trying to purify and characterize UVIC, a factor secreted from UV damaged cells which protects non-irradiated cells from damage. We have identified UVIC as a 17 kDa polypeptide that retains radioprotective activity after SDS-PAGE and renaturation. We are currently scaling up the isolation and purification process. 4 refs. (MHB)

Karin, M.

1991-01-01

140

The molecular basis for uv response of cultured human cells  

Energy Technology Data Exchange (ETDEWEB)

During the past year we have analyzed the mechanism by which UV and H{sub 2}O{sub 2} increase the activity of AP-1 in HeLa cells. AP-1 is a dimeric protein complex composed of the fos and jun gene products. After UV irradiation of HeLa cells (or exposure to H{sub 2}O{sub 2}) expression of the c-jun gene rapidly increases at least 50-fold. This induction occurs through the previously identified AP-1 site in the c-jun promoter. This positive autoregulation is mediated by AP-1 complexes that are composed mostly of cJun. cJun is a phosphoprotein that undergoes complex changes in its phosphorylation state following exposure to phorbol esters, growth factors or transforming oncogenes. We show that UV irradiation causes increases in the phosphorylation of cJun. We have been trying to determine the common signal by which DNA damaging agents lead to activation of the UV response. We present evidence that oxidative stress may serve as a signal for AP-1 induction during the UV response. We are also trying to purify and characterize UVIC, a factor secreted from UV damaged cells which protects non-irradiated cells from damage. We have identified UVIC as a 17 kDa polypeptide that retains radioprotective activity after SDS-PAGE and renaturation. We are currently scaling up the isolation and purification process. 4 refs. (MHB)

Karin, M.

1991-12-01

 
 
 
 
141

Digital Repatriation: Constructing a Culturally Responsive Virtual Museum Tour  

Directory of Open Access Journals (Sweden)

Full Text Available

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This paper describe a project that involved educators and three Native American communities in the construction of a virtual tour now available on the Web site of the National Museum of the American Indian(http://www. conexus.si.edu/. In fall 1998, the Pueblo of Laguna Department of Education, the College of Education and Graduate School of Library and Information Science at The University of Texas at Austin, and the Smithsonian?s National Museum of the American Indian (NMAI began the first collaboration that brought Native American students, teachers, and cultural representatives to the NMAI George Gustav Heye Center in New York City. The virtual tour makes extensive use of QuickTime Virtual Reality (QTVR. The panoramas of the exhibition space serve as an interface for accessing the featured objects selected by the students. Clicking on a hot spot over the museum display of a featured object causes the QTVR object to load in a separate Webpage frame accompanied by an interpreted essay written by a student. Clickable floor plans of the exhibition- space offer another method of navigating the virtual tour and accessing the virtual objects.

Loriene Roy?Mark Christal

2002-04-01

142

Adaptive response of yeast cultures (Saccharomyces Cerevisiae) exposed to low dose of gamma radiation  

International Nuclear Information System (INIS)

The present study was planned as follows: (i) setting up of standard experimental conditions for investigation of radio-induced adaptive response in lower Eucaryotes; (ii) developing of procedures for synchronizing Saccharomyces cerevisiae X 310 D cell cultures and cell cycle stages monitoring; (iii) investigation of gamma (Co-60) and UV irradiation effects on the viability of synchronized and non-synchronized cell cultures of Saccharomyces cerevisiae; the effects were correlated with the cell density and cell cycle stage; (iv) study of the adaptive response induced by irradiation and setting up of the experimental conditions for which this response is optimized. The irradiations were performed by using a Co-60 with doses of 102 - 104 Gy and dose rates ranging from 2.2 x 102 Gy/h to 8.7 x 103 Gy/h. The study of radioinduced adaptive response was performed by applying a pre-irradiation treatment of 100-500 Gy, followed by challenge doses of 2-4 kGy delivered at different time intervals, ranging from 1 h to 4 h. The survival rate of synchronized and non-synchronized cultures as a function of exposure dose shows an exponential decay shape. No difference in viability of the cells occurred between synchronized and non-synchronized cultures. The pre-irradiation of cells with 100 and 200 Gy were most efficient to induce an adaptive response for the yeast cells. In this stage of work we proved the occurrence of the adaptive response in the case of synchronized yeast cultures exposed to gamma radiation. The results will be used in the future to investigate the dependence of this response on the cell cycle and the possibility to induce such a response by a low level electromagnetic field. (authors)

2003-01-01

143

Effect of 60Co ?-rays irradiation pretreatment on callus inductivity and differentiation of strawberry anther  

International Nuclear Information System (INIS)

Strawberry buds, in which a majority of pollen had single nuclear keeping to the side, were pretreated by 60Co ?-rays irradiation at different doses. The irradiation effect on the callus inductivity and plant differentiation rate of strawberry anther were studied. The results indicated that the pretreatment by 60Co ?-rays could increase the anther callus inductivity and plant differentiation rate significantly, and 20 Gy was the best dose. The callus inductivity of Akihime and Toyonoka increased by 39.09% and 35.68%, respectively, compared with the no-pretreatment materials. On the same media, the plant differentiation rate of Akihime and Toyonoka were also increased by 6.67%-6.72% and 4.73%-6.45%, respectively, compared with the two varieties of no-pretreatment. (authors)

2007-06-01

144

Cultural Responsibility of Subjects in Moral Education in Colleges and Universities  

Directory of Open Access Journals (Sweden)

Full Text Available In a new era, to come to full understanding of the cultural responsibility of subjects in moral education in colleges and universities is an internal demand of modern educational theory for overall development of both teachers and students, and is the premise to play the leading role of teachers and mobilize the subjectivity of university students. At the same time, this also guides the direction for teachers and students to carry out moral education activities in colleges and universities. This article explains the responsibility of subjects in moral education in colleges and universities from the perspective of culture.

Chunyan Chen

2011-07-01

145

Emergence and patterning of the five cell types of the Zea mays anther locule  

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One fundamental difference between plants and animals is the existence of a germ-line in animals and its absence in plants. In flowering plants the sexual organs (stamens and carpels) are composed almost entirely of somatic cells, a small subset of which switch to meiosis, however, the mechanism of meiotic cell fate acquisition is a long-standing botanical mystery. In the maize (Zea mays) anther microsporangium the somatic tissues consist of four concentric cell layers which surround and supp...

Kelliher, Timothy; Walbot, Virginia

2011-01-01

146

Various Spatiotemporal Expression Profiles of Anther-Expressed Genes in Rice  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The male gametophyte and tapetum play different roles during anther development although they are differentiated from the same cell lineage, the L2 layer. Until now, it has not been possible to delineate their transcriptomes due to technical difficulties in separating the two cell types. In the present study, we characterized the separated transcriptomes of the rice microspore/pollen and tapetum using laser microdissection (LM)-mediated microarray. Spatiotemporal expression patterns of 28,141...

Hobo, Tokunori; Suwabe, Keita; Aya, Koichiro; Suzuki, Go; Yano, Kentaro; Ishimizu, Takeshi; Fujita, Masahiro; Kikuchi, Shunsuke; Hamada, Kazuki; Miyano, Masumi; Fujioka, Tomoaki; Kaneko, Fumi; Kazama, Tomohiko; Mizuta, Yoko; Takahashi, Hirokazu

2008-01-01

147

Extensive Divergence Between Mating-Type Chromosomes of the Anther-Smut Fungus  

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Genomic regions that determine mating compatibility are subject to distinct evolutionary forces that can lead to a cessation of meiotic recombination and the accumulation of structural changes between members of the homologous chromosome pair. The relatively recent discovery of dimorphic mating-type chromosomes in fungi can aid the understanding of sex chromosome evolution that is common to dioecious plants and animals. For the anther-smut fungus, Microbotryum lychnidis-dioicae (= M. violaceu...

Hood, Michael E.; Petit, Elsa; Giraud, Tatiana

2013-01-01

148

Variation in resistance to multiple pathogen species: anther smuts of Silene uniflora  

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The occurrence of multiple pathogen species on a shared host species is unexpected when they exploit the same micro-niche within the host individual. One explanation for such observations is the presence of pathogen-specific resistances segregating within the host population into sites that are differentially occupied by the competing pathogens. This study used experimental inoculations to test whether specific resistances may contribute to the maintenance of two species of anther-smut fungi,...

Chung, Erin; Petit, Elsa; Antonovics, Janis; Pedersen, Amy B.; Hood, Michael E.

2012-01-01

149

Microsporogenesis in two types of anther in Tinantia anomala (Torr. C.B. Clarke  

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Full Text Available Tinantia anomala (Torr. C.B. Clarke belongs to the genus Tinantia (Commelinaceae which is endemic to the tropical region of Central America. This species has adapted to the conditions in the greenhouse (Botanic Garden in Lublin, Poland (Faden 2006. We studied T. anomala due to the occurrence of two types of strikingly different stamens in one flower. During the investigations of T. anomala, we compared the morphology and anatomy of two types of stamens. In T. anomala’s flower six stamens are present. Three of them are located above the pistil and other three are located under the ovary near the stigma (Simpson et al. 1986. The upper stamens have round anthers, short filaments and many long brightly colored staminal hairs. The lower stamens are bigger with longitudinal anthers and alongated filaments. The last ones have only short, violet staminal hairs growing at the base of their filaments. Stamens of one type differ also with each other in size and shape of individual elements. The viability tests showed that during the microsporogenesis both types of anther produced viable pollen grains in 80%. This process differs in two types of anther because of the various chemical composition of tapetum. The pollen grains from the two types of stamen in T. anomala also differ in their texture, shape, exine pattern and chemical composition. The upper stamens produce grains with a concave triangular profile, while pollen grains from the lower stamens are smaller and exhibit convex triangular profile. Both types of pollen grains has three pores.

Joanna G?bura

2014-04-01

150

Flavonoids in white and yellow perianths and yellow anthers of tulips (Tulipa gesneriana L.  

Directory of Open Access Journals (Sweden)

Full Text Available The content of flavonoids in white and yellow perianths and yellow anthers of a few tulip cultivars were determined at the stage of full flowering. To analyses of flavonols a HPLC method was used. In anthers (yellow of all analyzed cultivars (Oscar, Pax, Profesor Wóycicki, Bia?a Dama, White Virgin, Calypso, Diana high content of quercetin (2,35 - 6,01 mg·g-1 F.W., kaempferol (1,09 - 9,47 mg·g-1 F.W. and apigenin (1,34 - 8,24 mg·g-1 F.W. was found. In analyzed white perianth of cvs. Oscar and White Virgin also high content of quercetin (1,3 - 1,80 mg·g-1 F.W. and kaempferol (1,90 mg·g-1 F.W. was documented and only traces of apigenin was found. In the yellow perianth of cv. Profesor Wóycicki the level of quercetin and kaempferol was much lower than in perianth of cvs. Oscar and White Virgin, and apigenin was absent. Thus, yellow anthers and white and yellow perianth of tulip cultivars are a rich source of flavonols.

Marcin Horbowicz

2001-12-01

151

Differential Proteomic Analysis of Anthers between Cytoplasmic Male Sterile and Maintainer Lines in Capsicum annuum L.  

Directory of Open Access Journals (Sweden)

Full Text Available Cytoplasmic male sterility (CMS, widely used in the production of hybrid seeds, is a maternally inherited trait resulting in a failure to produce functional pollen. In order to identify some specific proteins associated with CMS in pepper, two-dimensional gel electrophoresis (2-DE was applied to proteomic analysis of anthers/buds between a CMS line (designated NA3 and its maintainer (designated NB3 in Capsicum annuum L. Thirty-three spots showed more than 1.5-fold in either CMS or its maintainer. Based on mass spectrometry, 27 spots representing 23 distinct proteins in these 33 spots were identified. Proteins down-regulated in CMS anthers/buds includes ATP synthase D chain, formate dehydrogenase, alpha-mannosidas, RuBisCO large subunit-binding protein subunit beta, chloroplast manganese stabilizing protein-II, glutathione S-transferase, adenosine kinase isoform 1T-like protein, putative DNA repair protein RAD23-4, putative caffeoyl-CoA 3-O-methyltransferase, glutamine synthetase (GS, annexin Cap32, glutelin, allene oxide cyclase, etc. In CMS anthers/buds, polyphenol oxidase, ATP synthase subunit beta, and actin are up-regulated. It was predicted that male sterility in NA3 might be related to energy metabolism turbulence, excessive ethylene synthesis, and suffocation of starch synthesis. The present study lays a foundation for future investigations of gene functions associated with pollen development and cytoplasmic male sterility, and explores the molecular mechanism of CMS in pepper.

Zhiming Wu

2013-11-01

152

Dynamic cultural modulation of neural responses to one's own and friend's faces.  

Science.gov (United States)

Long-term cultural experiences influence neural response to one's own and friend's faces. The present study investigated whether an individual's culturally specific pattern of neural activity to faces can be modulated by temporary access to other cultural frameworks using a self-construal priming paradigm. Event-related potentials were recorded from British and Chinese adults during judgments of orientations of one's own and friend's faces after they were primed with independent and interdependent self-construals. We found that an early frontal negative activity at 220-340?ms (the anterior N2) differentiated between one's own and friend's faces in both cultural groups. Most remarkably, for British participants, priming an interdependent self-construal reduced the default anterior N2 to their own faces. For Chinese participants, however, priming an independent self-construal suppressed the default anterior N2 to their friend's faces. These findings indicate fast modulations of culturally specific neural responses induced by temporary access to other cultural frameworks. PMID:22258798

Sui, Jie; Hong, Ying-yi; Hong Liu, Chang; Humphreys, Glyn W; Han, Shihui

2013-03-01

153

Effects of scaffold architecture on mechanical characteristics and osteoblast response to static and perfusion bioreactor cultures.  

Science.gov (United States)

Tissue engineering focuses on the repair and regeneration of tissues through the use of biodegradable scaffold systems that structurally support regions of injury while recruiting and/or stimulating cell populations to rebuild the target tissue. Within bone tissue engineering, the effects of scaffold architecture on cellular response have not been conclusively characterized in a controlled-density environment. We present a theoretical and practical assessment of the effects of polycaprolactone (PCL) scaffold architectural modifications on mechanical and flow characteristics as well as MC3T3-E1 preosteoblast cellular response in an in vitro static plate and custom-designed perfusion bioreactor model. Four scaffold architectures were contrasted, which varied in inter-layer lay-down angle and offset between layers, while maintaining a structural porosity of 60?±?5%. We established that as layer angle was decreased (90° vs. 60°) and offset was introduced (0 vs. 0.5 between layers), structural stiffness, yield stress, strength, pore size, and permeability decreased, while computational fluid dynamics-modeled wall shear stress was increased. Most significant effects were noted with layer offset. Seeding efficiencies in static culture were also dramatically increased due to offset (?45% to ?86%), with static culture exhibiting a much higher seeding efficiency than perfusion culture. Scaffold architecture had minimal effect on cell response in static culture. However, architecture influenced osteogenic differentiation in perfusion culture, likely by modifying the microfluidic environment. Biotechnol. Bioeng. 2014;111: 1440-1451. © 2014 Wiley Periodicals, Inc. PMID:24473931

Bartnikowski, Michal; Klein, Travis J; Melchels, Ferry P W; Woodruff, Maria A

2014-07-01

154

Cytogenetic adaptive response of cultured fish cells to low doses of X-rays  

Energy Technology Data Exchange (ETDEWEB)

The adaptive response was examining chromosomal aberrations and micronucleus in cultured fish cells, ULF-23 (mudminnow) and CAF-31 (gold fish). When cultured fish cells were first irradiated with small doses of X-rays, they became less sensitive to subsequent exposures to high doses. The effective adaptive dose was 4.8 cGy-9.5 cGy. Adaptive doses given cells in the G1 phase were more effective than when given in the S phase. The adaptive response was maximal at 5 hours and disappeared at 10 hours after the adaptive dose. The expression of the response was inhibited by treatment with 3-aminobenzamide, as reported for mammalian cells, and with arabinofuranoside cytosine, an inhibitor of DNA polymerase alpha. Caffeine, an inhibitor of post-replicational repair, had no effect on the response. (author).

Kurihara, Yasuyuki; Etoh, Hisami (National Inst. of Radiological Sciences, Chiba (Japan)); Rienkjkarn, M.

1992-12-01

155

Cytogenetic adaptive response of cultured fish cells to low doses of X-rays  

International Nuclear Information System (INIS)

The adaptive response was examining chromosomal aberrations and micronucleus in cultured fish cells, ULF-23 (mudminnow) and CAF-31 (gold fish). When cultured fish cells were first irradiated with small doses of X-rays, they became less sensitive to subsequent exposures to high doses. The effective adaptive dose was 4.8 cGy-9.5 cGy. Adaptive doses given cells in the G1 phase were more effective than when given in the S phase. The adaptive response was maximal at 5 hours and disappeared at 10 hours after the adaptive dose. The expression of the response was inhibited by treatment with 3-aminobenzamide, as reported for mammalian cells, and with arabinofuranoside cytosine, an inhibitor of DNA polymerase alpha. Caffeine, an inhibitor of post-replicational repair, had no effect on the response. (author)

1992-12-01

156

Response of cellulase activity in pH-controlled cultures of the filamentous fungus Acremonium cellulolyticus.  

Science.gov (United States)

Cellulase production was investigated in pH-controlled cultures of Acremonium cellulolyticus. The response to culture pH was investigated for three cellulolytic enzymes, carbomethyl cellulase (CMCase), avicelase, and beta-glucosidase. Avicelase and beta-glucosidase showed similar profiles, with maximum activity in cultures at pH 5.5-6. The CMCase activity was highest in a pH 4 culture. At an acidic pH, the ratios of CMCase and avicelase activity to cellulase activity defined by filter paper unit were high, but at a neutral pH, the beta-glucosidase ratio was high. The pH 6.0 culture showed the highest cellulase activity within the range of pH 3.5-6.5 cultures. The saccharification activity from A. cellulolyticus was compared to those of the cellulolytic enzymes from other species. The A. cellulolyticus culture broth had a saccharification yield comparable to those of the Trichoderma enzymes GC220 and Cellulosin T2, under conditions with the same cellulase activity. The saccharification yields from Solka floc, Avicel, and waste paper, measured as the percent of released reducing sugar to dried substrate, were greater than 80% after 96 h of reaction. The yields were 16% from carboxymethylcellulose and 26% from wood chip refiner. Thus, the A. cellulolyticus enzymes were suitable for converting cellulolytic biomass to reducing sugars for biomass ethanol production. This study is a step toward the establishment of an efficient system to reutilize cellulolytic biomass. PMID:19882113

Prasetyo, Joni; Sumita, Shyuuhei; Okuda, Naoyuki; Park, Enoch Y

2010-09-01

157

An Evaluation Of Response Scale Formats Of The Culture Assessment Instrument  

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The aim of the study was to investigate which response scale, of the four, five, or six-point response scales would yield the best metric properties on the Culture Assessment Instrument. This was achieved by utilising data sets where the respective scales were used. The subjects included participants of various organisations, ages, educational levels, language and gender groups. No one scale could be identified as having the better metric properties. The lack of conclusive results is attribut...

Stan Smith; Gert Roodt

2003-01-01

158

Physiological and Transcriptional Responses of Saccharomyces cerevisiae to Zinc Limitation in Chemostat Cultures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Transcriptional responses of the yeast Saccharomyces cerevisiae to Zn availability were investigated at a fixed specific growth rate under limiting and abundant Zn concentrations in chemostat culture. To investigate the context dependency of this transcriptional response and eliminate growth rate-dependent variations in transcription, yeast was grown under several chemostat regimens, resulting in various carbon (glucose), nitrogen (ammonium), zinc, and oxygen supplies. A robust set of genes t...

2007-01-01

159

Writing the Male Abuser in Cultural Responses to Domestic Violence in Spain  

Science.gov (United States)

The article analyzes the portrayal of the male perpetrator of heterosexual domestic violence in a selection of contemporary Spanish texts (novel, drama, and autobiography) that form part of a clearly discernible cultural response to the issue of intimate partner violence in Spain today. It reads the figure of the abuser in conjunction with a range…

Godsland, Shelley

2012-01-01

160

Culturally Responsive Caring and Expectations for Academic Achievement in a Catholic School  

Science.gov (United States)

This article draws from a larger dissertation study that applied ethnographic and historical research methods to explore the intersection of culturally responsive pedagogy and Catholic schooling in immigrant communities. In particular, this article presents qualitative data analysis to describe student achievement expectations at a contemporary…

Dallavis, Christian

2014-01-01

 
 
 
 
161

A Cross-Cultural Examination of Preschool Teacher Cognitions and Responses to Child Aggression  

Science.gov (United States)

The associations among preschool teachers' attributions about child responsibility, intentionality, knowledge, and the seriousness of hypothetical displays of children's aggressive behavior are examined in United States ("N"?=?82) and Vietnamese ("N"?=?91) preschool teachers. The results suggest cross-cultural

Pochtar, Randi; Del Vecchio, Tamara

2014-01-01

162

Self-Determination through Self-Education: Culturally Responsive Schooling for Indigenous Students in the USA  

Science.gov (United States)

In this article, we outline culturally responsive schooling (CRS) for Indigenous youth and situate this concept within a larger history of US federal and community-based efforts to educate Indigenous youth in the USA. We examine what we know from the research literature about the impacts of CRS among US Indigenous youth. In exploring the research,…

Brayboy, Bryan McKinley Jones; Castagno, Angelina E.

2009-01-01

163

In vitro culture in barley breeding  

International Nuclear Information System (INIS)

One of the most useful biotechnics for plant breeders is in vitro culture of anthers or miscropores to induce haploids and homozygous diploids. High frequency of microspore-derived diploid plants could be produced by culturing anthers on Ficoll medium. The segregation ratios of certain morphological characters were not random and could be shifted by culture conditions. It was reported by a number of authors that true breeding and highly productive genotypes were obtained from microspore-derived diploid plants and doubled haploids derived from bulbosom techniques. There is a great possibility that a selective system for desirable characters can be built in an in vitro culture system. Where haploids can be induced in crop plants, they provide the most rapid technique for producing homozygous lines. Since the genetically controlled factors in homozygous lines are fixed and will be identical in the future generations, it becomes possible for a plant breeder to evaluate quantitative characters such as yield and quality very early in the breeding program. There are two methods which have been used extensively for production of homozygous diploid barley plants. They are bulbosum techniques and anther culture methods. (author). 14 refs, 5 tabs

1988-03-01

164

Chemical residues and biochemical responses in wild and cultured European sea bass (Dicentrarchus labrax L.)  

International Nuclear Information System (INIS)

Cultured and wild sea bass (Dicentrarchus labrax) from the Arade Estuary were sampled in summer and winter and the degree of exposure to metals and polycyclic aromatic hydrocarbons (PAHs) assessed, together with some biochemical responses against those and other pollutants. The highest levels of copper (up to 997 ?g g-1 dry weight) and cadmium (up to 4.22 ?g g-1 dry weight) were detected in the liver and kidney of cultured specimens, whereas the highest exposure to PAHs was observed in wild fish. Significant alterations in some biochemical markers were detected and associated to pollutant exposure. Thus, metallothionein concentrations were higher in the tissues of cultured fish and positively correlated with metal residues. The activity 7-ethoxyresorufin O-deethylase ranged from 28 pmol/min/mg protein in cultured fish to 83 pmol/min/mg protein in wild fish collected near a marina area. Cultured fish and wild fish from the marina area had depressed acetylcholinesterase in muscle tissue and a parasitic infection in the gonads. The obtained results support the usefulness of the combined use of chemical and biochemical markers to assess the impact of anthropogenic pollutants in both wild and cultured fish

2007-02-01

165

Biomechanical response of collagen fascicles to restressing after stress deprivation during culture.  

Science.gov (United States)

In vitro tissue culture experiments were performed to study the biomechanical response of collagen fascicles to restressing after exposure to non-loaded condition. Collagen fascicles of approximately 300 microm in diameter were aseptically dissected from rabbit patellar tendons. They were cultured under no-load condition for 1 week, and then under a static stress of approximately 1.2 MPa for the subsequent 1 or 2 weeks. After culture, their mechanical properties were determined with a micro-tensile tester, and were compared to those of fascicles cultured under no-load condition and non-cultured, control fascicles. Tangent modulus and tensile strength of the non-loaded fascicles were significantly lower than those of the control fascicles at 1 week and gradually decreased thereafter. However, the modulus and strength were increased by restressing. After 2-week restressing, both parameters were significantly greater than those of the time-matched, non-loaded fascicles, although these values were still significantly lower than those of the control fascicles. That is, the application of stress after exposure to non-loaded condition suppressed the deterioration of the biomechanical properties of fascicles, although it did not improve. These results indicate that a short period of stressing is not sufficient for cultured collagen fascicles to completely recover their mechanical properties, if they are once exposed to no-stress condition even for a short period of time. These are similar to previous results observed in tendons and ligaments inside the body. PMID:17399722

Yamamoto, Ei; Kogawa, Daisuke; Tokura, Susumu; Hayashi, Kozaburo

2007-01-01

166

Expression of an anther-specific chalcone synthase-like gene is correlated with uninucleate microspore development in Nicotiana sylvestris.  

Science.gov (United States)

Two cDNA clones, specifically expressed in Nicotiana sylvestris anthers during uninucleate microspore development, were isolated using a subtractive hybridization approach. Sequence analysis showed that one of them, NSCHSLK, displayed a high level of similarity to several anther-specific chalcone synthase-like (CHSLK) proteins and an ORF from chromosome I of Arabidopsis thaliana. A lower, but significant, similarity to chalcone synthases and closely related enzymes (CHSRE) was also detected. The structure of the nschslk gene was found to be typical of the chalcone (chs)/stilbene (sts) synthase family. Expression of NSCHSLK mRNA was confined to microspores and tapetal cells. UV-irradiation or infection with Phytophthora parasitica var. nicotianae of transgenic Nicotiana benthamiana plants carrying a chimeric nschslk/GUS gene indicated that the nschslk promoter exhibits the same anther-specific, developmentally regulated expression pattern. Comparison of CHSRE and CHSLK polypeptide sequences revealed some important similarities and differences between the two groups. The data presented in this study, suggest that the anther-specific chslk genes represent a separate sub-family of plant polyketide synthases related to chs/sts in terms of gene structure, polypeptide sequence and the possible catalytic mechanism, but differing in substrate/product specificity. The putative role of CHSLK enzymes in anther development and particularly in exine synthesis is discussed. PMID:9869422

Atanassov, I; Russinova, E; Antonov, L; Atanassov, A

1998-12-01

167

Investigating the effect of heavy metals on developmental stages of anther and pollen in Chenopodium botrys L. (Chenopodiaceae).  

Science.gov (United States)

Excessive amounts of heavy metals adversely affect plant growth and development. Whereas some regions naturally contain high levels of heavy metals, anthropogenic release of heavy metals into the environment continuously increases soil contamination. Preliminary studies have shown that Chenopodium botrys can grow in some heavy metal contaminated soils and is a high accumulator plant species for Cu and moderately accumulator plant species for Fe, Mn, and Zn, thus, was considered as an important species in this study. Based on that, in this species, we studied the individual effects of heavy metals on the formation, development, and structure of anther and pollen. To achieve this purpose, surrounding area of Hame-Kasi iron and copper mine (Hamedan, Iran) was chosen as a polluted area where the amount of some heavy metals was several times higher than the natural soils. Flowers and young pods were removed from non-polluted and polluted plants, fixed in FAA 70, and subjected to developmental studies. Analysis of anther development in plants from contaminated sites showed general similarities in the pattern of pollen formation with those from non-polluted ones, but also deviation from typical form of major stages of anther and pollen development was seen in plants from polluted ones. Stabilizing of tapetum layer, increasing in tapetum layer numbers, thickening callose wall in the microspore mother cell stage, changing the anther shape, and decreasing the size of anther were the effects of heavy metals. Reduction of pollen number was also seen in the plants collected from polluted area. PMID:20499206

Yousefi, Nafiseh; Chehregani, Abdolkarim; Malayeri, Behrouz; Lorestani, Bahareh; Cheraghi, Mehrdad

2011-06-01

168

Two male-sterile mutants of Zea Mays (Poaceae) with an extra cell division in the anther wall.  

Science.gov (United States)

Two recessive male-sterile mutants of maize with similar patterns of pollen abortion were studied. Genetic studies showed that one of the two mutations was allelic with a previously identified male-sterility locus (ms23) and the other mutation was in a newly identified male-sterility locus (ms32). Cytological characterization of homozygous mutants and fertile heterozygous control siblings was performed using brightfield, fluorescence, and electron microscopy. During normal anther development, the final anther wall periclinal division divides the secondary parietal anther wall layer into the middle layer and tapetum, forming an anther with four wall layers. This is followed by differentiation of the tapetal cells into protoplastic binucleate, secretory tissue. In both the ms23 and ms32 mutants, the prospective tapetal layer divided into two layers, termed t1 and t2, forming an anther with five wall layers. Neither the t1 nor the t2 layers differentiated normally into tapetal layers, as determined by examination of cell walls, nucleus number, and cytoplasmic organization. Pollen mother cells aborted after the onset of prophase I of meiosis, suggesting that an early developmental coordination may exist between tapetum and pollen mother cells. PMID:10948005

Chaubal, R; Zanella, C; Trimnell, M R; Fox, T W; Albertsen, M C; Bedinger, P

2000-08-01

169

Primary culture of secretagogue-responsive parietal cells from rabbit gastric mucosa  

International Nuclear Information System (INIS)

A new procedure for isolation and primary culture of gastric parietal cells is described. Parietal cells from rabbit gastric mucosa are enriched to greater than 95% purity by combining a Nycodenz gradient separation with centrifugal elutriation. Cells are plated on the basement membrane matrix, Matrigel, and maintained in culture for at least 1 wk. Parietal cells cultured in this manner remain differentiated, cross-react with monoclonal H+-K+-ATPase antibodies, and respond to histamine, gastrin, and cholinergic stimulation with increased acid production as measured by accumulation of the weak base, [14C]aminopyrine. When stimulated, cultured cells undergo ultrastructural changes in which intracellular canaliculi expand and numerous microvilli are observed. These ultrastructural changes are similar to those previously found to occur in vivo and in acutely isolated parietal cells. Morphological transformations in living cells can also be observed with differential interference contrast optics in the light microscope. After histamine stimulation, intracellular canaliculi gradually expand to form large vacuolar spaces. When the H2 receptor antagonist, cimetidine, is added to histamine-stimulated cells, these vacuoles gradually disappear. The ability to maintain hormonally responsive parietal cells in primary culture should make it possible to study direct, long-term effects of a variety of agonists and antagonists on parietal cell secretory-related activity. These cultured cells should also prove to be useful for the study of calcium transients, ion fluxes, and intracellular pH as related to acid secretion in single cells, particularly since morphological transformations can be used to monitor physiological responses at the same time within the same cell

1989-01-01

170

Anther-specific carbohydrate supply and restoration of metabolically engineered male sterility.  

Science.gov (United States)

Male-sterile plants are used in hybrid breeding as well as for gene confinement for genetically modified plants in field trials and agricultural production. Apart from naturally occurring mutations leading to male sterility, biotechnology has added new possibilities for obtaining male-sterile plants, although so far only one system is used in practical breeding due to limitations in propagating male-sterile plants without segregations in the next generation or insufficient restoration of fertility when fruits or seeds are to be harvested from the hybrid varieties. Here a novel mechanism of restoration for male sterility is presented that has been achieved by interference with extracellular invertase activity, which is normally specifically expressed in the anthers to supply the developing microspores with carbohydrates. Microspores are symplastically isolated in the locular space of the anthers, and thus an unloading pathway of assimilates via the apoplasmic space is mandatory for proper development of pollen. Antisense repression of the anther-specific cell wall invertase or interference with invertase activity by expressing a proteinacious inhibitor under the control of the anther-specific invertase promoter results in a block during early stages of pollen development, thus causing male sterility without having any pleiotropic effects. Restoration of fertility was successfully achieved by substituting the down-regulated endogenous plant invertase activity by a yeast invertase fused to the N-terminal portion of potato-derived vacuolar protein proteinase II (PiII-ScSuc2), under control of the orthologous anther-specific invertase promoter Nin88 from tobacco. The chimeric fusion PiII-ScSuc2 is known to be N-glycosylated and efficiently secreted from plant cells, leading to its apoplastic location. Furthermore, the Nin88::PiII-ScSuc2 fusion does not show effects on pollen development in the wild-type background. Thus, such plants can be used as paternal parents of a hybrid variety, thereby the introgression of Nin88::PiII-ScSuc2 to the hybrid is obtained and fertility is restored. In order to broaden the applicability of this male sterility/restoration system to other plant species, a phylogenic analysis of plant invertases(beta-fructofuranosidases) and related genes of different species was carried out. This reveals a specific clustering of the cell wall invertases with anther-specific expression for dicotyl species and another cluster for monocotyl plants. Thus, in both groups of plants, there seems to be a kind of co-evolution, but no recent common ancestor of these members of the gene family. These findings provide a helpful orientation to classify corresponding candidate genes in further plant species, in addition to the species analysed so far (Arabidopsis, tobacco, tomato, potato, carrots, rice, and wheat). PMID:20427415

Engelke, T; Hirsche, J; Roitsch, T

2010-06-01

171

Callus induction and embryo regeneration in Coffea arabica L. anthers by silver nitrate and ethylene / Indução de calos e regeneração de embriões em anteras de Coffea arabica L. por nitrato de prata e etileno  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O melhoramento genético do cafeeiro por métodos convencionais é um processo demorado para aquisição de uma nova cultivar. Através da cultura de anteras podem-se obter linhagens homozigóticas rapidamente, oriundas de dihaplóides. O objetivo foi utilizar na cultura de anteras na cv. Catuaí Vermelho 99 [...] de Coffea arabica L., nitrato de prata (AgNO3) e etileno para induzir a formação de calos e regenerar plântulas dihaplóides. As anteras foram inoculadas em meio MS acrescido de 2 mg L-1 de 2,4-D com e sem AgNO3 (5 mg L-1), juntamente com etileno por diferentes dias: (testemunha; 2; 4; 6, e 8). Ao final de 12 dias, estas foram transferidas para o meio de regeneração, acrescido de 0,108 mg L-1 de cinetina. Foi observada uma oxidação e intumescimento maior nos primeiros dias de inoculação em exposição ao etileno, e a cv. Catuaí Vermelho 99 respondeu a formação de calos e também a embriogênese direta na presença do etileno. Abstract in english The genetic breeding of coffee by conventional methods to obtain new cultivars is time-consuming. Anther culture can yield homozygous lines quickly from bi-haploids. This study used anther cultures of Coffea arabica L. cv. Catuaí Vermelho 99, and tested the effect of silver nitrate (AgNO3) and ethyl [...] ene in callus-formation induction and bi-haploid seedling regeneration. The anthers were inoculated in MS to which 2 mg L-1 2,4-D had been added with AgNO3 (5 mg L-1) together with ethylene being introduced or not, for different periods (the control, 2, 4, 6, and 8 days). At the end of 12 days, the anthers were transferred to the regeneration medium, to which 0.108 mg L-1 kinetin had been added. Greater oxidation and intumescence were observed in the first days after exposure to ethylene; the cultivar Catuaí Vermelho 99 responded to callus formation and also direct embryogenesis in the presence of ethylene.

Silva, Adelaide Siqueira; Luz, José Magno Queiroz; Rodrigues, Tatiana Michlovská; Bittar, Cecília Alves; Lino, Leandro de Oliveira.

172

Intra and interspecific variability of in vitro culture response in Lycopersicon (tomatoes  

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Full Text Available Intra and interspecific variability was measured in the genus Lycopersicon for the traits: productivity rate (PR, total number of regenerated shoots/total number of cultures, regeneration percentage (%R, number of cultures regenerating shoots or primordia/total number of cultures and callus percentage (%C, number of cultures only producing callus/total number of cultures. Leaf explants from various genotypes of L. esculentum, L. esculentum var. cerasiforme, L. pimpinellifolium and L. peruvianum were placed on Murashige and Skoog (Physiol. Plant. 15: 473-493, 1962 medium + 0.175 mg/l IAA + 2.25 mg/l BA. Significant differences among species and among genotypes within the same species were found, while genotypes from different species showed similar responses.A variabilidade intra e interespecífica foi avaliada no gênero Lycopersicon para as variáveis: taxa de produtividade (PR, número total de brotos/número total de culturas, percentagem de regeneração (%R, número de culturas que regeneraram brotos ou primórdios/número total de culturas e percentagem de calo (%C, número de culturas que só desenvolveram calo/número total de culturas. Os explantes foliares de vários genótipos de L. esculentum, L. esculentum var. ceraciforme, L. pimpinellifolium e L. peruvianum foram colocados em meio de cultura Murashige and Skoog (Physiol. Plant. 15: 473-493, 1962 + 0.175 mg/l AIA + 2.25 mg/l BA. Detectaram-se diferenças significativas entre espécies e entre genótipos de uma mesma espécie, apresentando genótipos de diferentes espécies a mesma resposta.

Guillermo Pratta

1997-03-01

173

An Empirical Research on Chinese-English Bilinguals’ Compliment Responses—A Cross-cultural Perspective  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Compliments and compliment responses (CRs) are decided by linguistic and sociocultural norms, and further reflect cultural values and social norms. The study of CRs has generated a great number of studies in pragmatics. Previous studies, including Chinese as participants, have investigated Chinese CRs and compared Chinese CRs with people of other languages. According to Holmes’ (1988) taxonomy, CRs can be classified into three categories: Agreeing, Deflecting/Evading and Rejecting. L...

Xuehua An

2013-01-01

174

Genome-Wide Transcriptional Response of Chemostat-Cultured Escherichia coli to Zinc  

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Zinc is an essential trace metal ion for growth, but an excess of Zn is toxic and microorganisms express diverse resistance mechanisms. To understand global bacterial responses to excess Zn, we conducted transcriptome profiling experiments comparing Escherichia coli MG1655 grown under control conditions and cells grown with a toxic, sublethal ZnSO4 concentration (0.2 mM). Cultures were grown in a defined medium lacking inorganic phosphate, permitting maximum Zn bioavailability, and in glycero...

2005-01-01

175

Corporate Social Responsibility and Culture : A Study of European Multinational Corporations’ adaptation of Community Involvement Practices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Corporate social responsibility (CSR), which has emerged as a global trend, has gained increased focus in the everyday media and among practitioners on the political agenda. CSR has also risen as an important research topic in the field of organization. This study investigates European multinational corporations’ tendencies to adapt CSR policies and practices, or more specifically corporate community involvement, to different national cultures. The paper explores if/how and why companies wi...

2012-01-01

176

Maize csmd1 exhibits pre-meiotic somatic and post-meiotic microspore and somatic defects but sustains anther growth.  

Science.gov (United States)

Maize male reproductive development is complex and lengthy, and anther formation and pollen maturation are precisely and spatiotemporally regulated. Here, we document that callose, somatic, and microspore defect 1 (csmd1), a new male-sterile mutant, has both pre-meiotic somatic and post-meiotic gametophyte and somatic defects. Chromosome behavior and cell developmental events were monitored by nuclear staining viewed by bright field microscopy; cell dimensions were charted by Volocity analysis of confocal microscopy images. Aniline blue staining and quantitative assays were performed to record callose deposition, and expression of three callose synthase genes was measured by qRT-PCR. Despite numerous defects and unlike other maize male-sterile mutants that show growth arrest coincident with locular defects, csmd1 anther elongation is nearly normal. Pre-meiotically and during prophase I, there is excess callose surrounding the meiocytes. Post-meiotically csmd1 epidermal cells have impaired elongation but excess longitudinal divisions, and uninucleate microspores cease growth; the microspore nucleoli degrade followed by cytoplasmic vacuolization and haploid cell collapse. The single vascular bundle within csmd1 anthers senesces precociously, coordinate with microspore death. Although csmd1 anther locules contain only epidermal and endothecial cells at maturity, locules are oval rather than collapsed, indicating that these two cell types suffice to maintain an open channel within each locule. Our data indicate that csmd1 encodes a crucial factor important for normal anther development in both somatic and haploid cells, that excess callose deposition does not cause meiotic arrest, and that developing pollen is not required for continued maize anther growth. PMID:21475967

Wang, Dongxue; Skibbe, David S; Walbot, Virginia

2011-12-01

177

Proteome analysis of the wild and YX-1 male sterile mutant anthers of wolfberry (Lycium barbarum L.).  

Science.gov (United States)

Pollen development is disturbed in the early tetrad stage of the YX-1 male sterile mutant of wolfberry (Lycium barbarum L.). The present study aimed to identify differentially expressed anther proteins and to reveal their possible roles in pollen development and male sterility. To address this question, the proteomes of the wild-type (WT) and YX-1 mutant were compared. Approximately 1760 protein spots on two-dimensional differential gel electrophoresis (2D-DIGE) gels were detected. A number of proteins whose accumulation levels were altered in YX-1 compared with WT were identified by mass spectrometry and the NCBInr and Viridiplantae EST databases. Proteins down-regulated in YX-1 anthers include ascorbate peroxidase (APX), putative glutamine synthetase (GS), ATP synthase subunits, chalcone synthase (CHS), CHS-like, putative callose synthase catalytic subunit, cysteine protease, 5B protein, enoyl-ACP reductase, 14-3-3 protein and basic transcription factor 3 (BTF3). Meanwhile, activities of APX and GS, RNA expression levels of apx and atp synthase beta subunit were low in YX-1 anthers which correlated with the expression of male sterility. In addition, several carbohydrate metabolism-related and photosynthesis-related enzymes were also present at lower levels in the mutant anthers. In contrast, 26S proteasome regulatory subunits, cysteine protease inhibitor, putative S-phase Kinase association Protein 1(SKP1), and aspartic protease, were expressed at higher levels in YX-1 anthers relative to WT anthers. Regulation of wolfberry pollen development involves a complex network of differentially expressed genes. The present study lays the foundation for future investigations of gene function linked with wolfberry pollen development and male sterility. PMID:22860020

Zheng, Rui; Sijun Yue; Xu, Xiaoyan; Liu, Jianyu; Xu, Qing; Wang, Xiaolin; Han, Lu; Yu, Deyue

2012-01-01

178

Neuromyelitis optica IgG stimulates an immunological response in rat astrocyte cultures.  

Science.gov (United States)

Neuromyelitis optica (NMO) is a primary astrocyte disease associated with central nervous system inflammation, demyelination, and tissue injury. Brain lesions are frequently observed in regions enriched in expression of the aquaporin-4 (AQP4) water channel, an antigenic target of the NMO IgG serologic marker. Based on observations of disease reversibility and careful characterization of NMO lesion development, we propose that the NMO IgG may induce a dynamic immunological response in astrocytes. Using primary rat astrocyte-enriched cultures and treatment with NMO patient-derived serum or purified IgG, we observed a robust pattern of gene expression changes consistent with the induction of a reactive and inflammatory phenotype in astrocytes. The reactive astrocyte factor lipocalin-2 and a broad spectrum of chemokines, cytokines, and stress response factors were induced by either NMO patient serum or purified IgG. Treatment with IgG from healthy controls had no effect. The effect is disease-specific, as serum from patients with relapsing-remitting multiple sclerosis, Sjögren's, or systemic lupus erythematosus did not induce a response in the cultures. We hypothesize that binding of the NMO IgG to AQP4 induces a cellular response that results in transcriptional and translational events within the astrocyte that are consistent with a reactive and inflammatory phenotype. Strategies aimed at reducing the inflammatory response of astrocytes may short circuit an amplification loop associated with NMO lesion development. PMID:24492996

Howe, Charles L; Kaptzan, Tatiana; Magaña, Setty M; Ayers-Ringler, Jennifer R; LaFrance-Corey, Reghann G; Lucchinetti, Claudia F

2014-05-01

179

Contrasting Nephropathic Responses to Oral Administration of Extract of Cultured Penicillium polonicum in Rat and Primate  

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Full Text Available Liquid- or solid substrate-cultured Penicillium polonicum administered in feed to rats over several days evokes a histopathological response in kidney involving apoptosis and abnormal mitosis in proximal tubules. The amphoteric toxin is yet only partly characterized, but can be isolated from cultured sporulating biomass in a fraction that is soluble in water and ethanol, and exchangeable on either anion- or cation-exchange resins. After several weeks of treatment renal proximal tubule distortion became striking on account of karyocytomegaly, but even treatment for nearly two years remained asymptomatic. Extract from a batch of solid substrate fermentation of P. polonicum on shredded wheat was incorporated into feed for rats during four consecutive days, and also given as an aqueous solution by oral gavage to a vervet monkey daily for 10 days. Treatment was asymptomatic for both types of animal. Rat response was evident as the typical renal apoptosis and karyomegaly. In contrast there was no such response in the primate; and neither creatinine clearance nor any haematological characteristic or serum component concentration deviated from a control or from historical data for this primate. The contrast is discussed concerning other negative findings for P. polonicum in pigs and hamsters. Renal karyomegaly, as a common rat response to persistent exposure to ochratoxin A, is not known in humans suspected as being exposed to more than the usual trace amounts of dietary ochratoxin A. Therefore the present findings question assumptions that human response to ochratoxin A conforms to that in the rat.

John E. Fincham

2010-08-01

180

Osmotic stress responses of individual white oak (Quercus section, Quercus subgenus) genotypes cultured in vitro.  

Science.gov (United States)

White oaks (Quercus section, Quercus subgenus) are widely distributed in Europe. Quercus petraea (sessile oak), an economically important species is predicted to be affected by climate change. Q. pubescens (pubescent oak) and Q. virgiliana (Italian pubescent oak) are economically less important, drought tolerant species. Frequent hybridization of white oaks was observed and currently the introgression of Q. pubescens and Q. virgiliana in non-mediterranean regions of Europe has been reported. Our goal was to use tissue cultures established from individual trees of the above taxa and their putative hybrids, all present in the forest stand of Síkf?kút LTER Research Area (NE Hungary) as simple experimental model systems for studying drought/osmotic stress tolerance. Tissue cultures are more suitable models for such studies, than seedlings, because they are genetically identical to the parent plants. Polyethylene glycol (PEG6000) treatments were used for this purpose. The identification of taxa was based on leaf morphological traits and microsatellite analysis and showed that Q. petraea is genetically distinct to all other taxa examined. We established six callus lines of Quercus. As expected, in Q. petraea cultures PEG6000 induced severe loss of fresh weight and the ability to recover after removal of the osmoticum, which was not characteristic for Q. pubescens and Q. virgiliana. Putative hybrids exhibited an intermediate response to osmotic stress. Activity gels showed the increase of single-strand preferring (SSP) nuclease and no significant change of guaiacol-peroxidase activities in drought-sensitive genotypes/cultures and no significant increase of SSP nuclease activities accompanied with increases of guaiacol-peroxidase activities in drought-tolerant ones. This indicates that drought/osmotic stress tolerance is associated to increased capacity of scavenging reactive oxygen species and hence less susceptibility to DNA damage. Our results confirm that tissue cultures of oak are suitable model systems for studying drought/osmotic stress responses. PMID:24331415

Demeter, Zita; Kanalas, Péter; Máthé, Csaba; Cseke, Klára; Sz?ll?si, Erzsébet; M-Hamvas, Márta; Jámbrik, Katalin; Kiss, Zoltán; Mészáros, Ilona

2014-01-15

 
 
 
 
181

Organizational Institutions and Their Responsible Behavioral-Cultural Gene Codes and A Measurement for Organizational Efficiency  

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Full Text Available This essay has two goals. The first is to classify two different types of organizational institutions from the four-dimensional system-thinking perspective, and to identify the relationship between such organizational institutions and their relevant behavioral-cultural gene codes embedded within their (P-individuals. Unlike the popular belief that authoritarian or totalitarian institutions are caused by ideologies or created/dominated by tyrannical leaders, the author defines a concept of behavioral-cultural gene code and extends the application of self-organization theory to suggest that behavioral-cultural gene codes carried by the members of the organization are responsible for the formation of, either democratic or authoritarian, institutions. Therefore, transformation of an authoritarian organization into a democratic one, no matter at the level of groups, of business enterprises, or of a government, must start from transforming behavioral-cultural gene codes. The second goal is to define Organizational Friction Coefficient for capturing the characteristics of these two types of organizational institutions, thus adding clarity to the widely used concept of organizational efficiency in the contexts of both business organizations and systems of government.

Jason Jixuan

2010-10-01

182

DNA double-strand break repair and radiation response in human tumour primary cultures  

International Nuclear Information System (INIS)

The accumulation and repair of radiation-induced DNA double-strand breaks (dsbs) were determined by neutral filter elution on 20 primary cultures obtained from ovarian cancer and malignant melanoma clinical specimens. The initial frequency of DNA dsbs after exposure to 50 Gy ?-irradiation varied greatly for the individual cultures. However, melanomas were generally more efficient than ovarian cancers in repairing these DNA lesions (mean percentage of DNA dsb rejoined after 2 h: 83 versus 62%). In 13 of 20 cultures radiosensitivity was also assessed by the Courtenay clonogenic assay. The mean ''+'' SD of the surviving fraction at 2 Gy (SF2) was slightly higher for melanomas (0.56 ± 0.25) than for ovarian carcinomas (0.43 ± 0.23). No correlation was observed between SF2 and in vitro plating efficiencies or any biological characteristics of the tumour cell population, such as proliferative activity and DNA ploidy. Similarly, we failed to find any relation between the initial frequencies of DNA dsbs and SF2 in individual tumours. In contrast, a significant and direct relationship (r = 0.86, p 2 and the percentages of DNA dsbs rejoined after irradiation. In agreement with reported data on human tumour cell lines, our results indicate that the ability to repair DNA dsbs is an important determinant for radiation response even in primary cultures of clinical tumours. (author)

1994-09-01

183

An Empirical Research on Chinese-English Bilinguals’ Compliment Responses—A Cross-cultural Perspective  

Directory of Open Access Journals (Sweden)

Full Text Available Compliments and compliment responses (CRs are decided by linguistic and sociocultural norms, and further reflect cultural values and social norms. The study of CRs has generated a great number of studies in pragmatics. Previous studies, including Chinese as participants, have investigated Chinese CRs and compared Chinese CRs with people of other languages. According to Holmes’ (1988 taxonomy, CRs can be classified into three categories: Agreeing, Deflecting/Evading and Rejecting. Looking from a cross-cultural perspective, Chinese tend to use less Accepting strategies and more Rejecting strategies than Australians do (Tang and Zhang, 2009. Within the same language community, CR strategies might also change over time, as has been suggested in Chen and Yang’s (2010. However, research on Chinese English-knowing bilinguals’ CRs in the two languages is rare. The present study, focuses on a group of Chinese English-knowing bilinguals’ CR speech act. It aims at finding out whether Chinese English bilinguals will respond to compliments differently, when they are exposed to different media—Chinese language and English language, which might shed new light on how language influences and shapes people’s social and cultural norms. Written discourse completion task (DCT is used to elicit the participants’ responses to compliments on one’s look, ability, character, possession. The survey was conducted on a cohort of 31 Chinese English teachers, during the period when they were in Singapore. Results show that there are differences in CR strategies employed in Chinese DCT and English DCT.

Xuehua An

2013-09-01

184

Response of cultured human airway epithelial cells to X-rays and energetic ?-particles  

International Nuclear Information System (INIS)

Radon and its progeny, which emit ?-particles during decay, may play an important role in inducing human lung cancer. To gain a better understanding of the biological effects of ?-particles in human lung we studied the response of cultured human airway epithelial cells to X-rays and monoenergetic helium ions. Experimental results indicated that the radiation response of primary cultures was similar to that for airway epithelial cells that were transformed with a plasmid containing an origin-defective SV40 virus. The RBE for cell inactivation determined by the ratio of D0 for X-rays to that for 8 MeV helium ions was 1.8-2.2. The cross-section for helium ions, calculated from the D0 value, was about 24 ?m2 for cells of the primary culture. This cross-section is significantly smaller than the average geometric nuclear area (? 180 ?m2), suggesting that an average of 7.5 ?-particles (8 MeV helium ions) per cell nucleus are needed to induce a lethal lesion. (author)

1990-09-01

185

Alteration of Cellular Behavior and Response to PI3K Pathway Inhibition by Culture in 3D Collagen Gels  

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Most investigations into cancer cell drug response are performed with cells cultured on flat (2D) tissue culture plastic. Emerging research has shown that the presence of a three-dimensional (3D) extracellular matrix (ECM) is critical for normal cell behavior including migration, adhesion, signaling, proliferation and apoptosis. In this study we investigate differences between cancer cell signaling in 2D culture and a 3D ECM, employing real-time, live cell tracking to directly observe U2OS hu...

2012-01-01

186

Evaluating autism diagnostic and screening tools for cultural and linguistic responsiveness.  

Science.gov (United States)

While clear guidelines and best practices exist for the assessment of autism spectrum disorders (ASD), little information is available about assessing for ASD in culturally and linguistically diverse (CLD) populations. CLD populations might be misidentified and under-identified with ASD due to the assessment practices that we employ. Four autism diagnostic tools and six autism screeners were selected and evaluated for their cultural and linguistic responsiveness. Although the evaluation of ASD within CLD populations is highly complex, this study identified the need for improved autism assessment tools and practices. Without the appropriate assessment of these populations, CLD children will likely continue to be misidentified (or not identified at all) and will miss crucial intervention opportunities. PMID:24186120

Harris, Bryn; Barton, Erin E; Albert, Chantel

2014-06-01

187

An anther-specific dihydroflavonol 4-reductase-like gene (DRL1) is essential for male fertility in Arabidopsis.  

Science.gov (United States)

Arabidopsis contains only one functional dihydroflavonol 4-reductase (DFR) gene, but several DFR-like genes encoding proteins with the conserved NAD(P)H binding domain. At4g35420, named DRL1 (Dihydroflavonol 4-reductase-like1), is a closely related homolog of the rice anther-specific gene OsDFR2 reported previously. Two T-DNA mutants (drl1-1 and drl1-2) were found to have impaired pollen formation and seed production. Histological analysis revealed defective microspore development after tetrad release in both mutants. Microspore walls were found to rupture, releasing the protoplasts which eventually degenerated. The DRL1 promoter is anther-specific in closed flower buds. Promoter-GUS analysis in transgenic Arabidopsis revealed expression in tapetum, tetrads, and developing microspores, but not in mature anthers. Enhanced yellow fluorescent protein (EYFP)-localization analysis demonstrated that DRL1 is a soluble cytosolic protein that may also be localized in the nucleus. Restoration of male fertility and seed formation was only achieved by a native promoter-DRL1 construct, but not by a 35S-DRL1 construct, demonstrating the importance of spatial and temporal specificities of DRL1 expression. DRL1 may be involved in a novel metabolic pathway essential for pollen wall development. DRL1 homologs were identified as anther- and floral-specific expressed sequence tags from different species, suggesting that DRL1 may have a conserved functional role in male fertility in flowering plants. PMID:19054337

Tang, Lee Kwan; Chu, Hung; Yip, Wing Kin; Yeung, Edward C; Lo, Clive

2009-01-01

188

OsATG7 is required for autophagy-dependent lipid metabolism in rice postmeiotic anther development.  

Science.gov (United States)

In flowering plants, the tapetum, the innermost layer of the anther, provides both nutrient and lipid components to developing microspores, pollen grains, and the pollen coat. Though the programmed cell death of the tapetum is one of the most critical and sensitive steps for fertility and is affected by various environmental stresses, its regulatory mechanisms remain mostly unknown. Here we show that autophagy is required for the metabolic regulation and nutrient supply in anthers and that autophagic degradation within tapetum cells is essential for postmeiotic anther development in rice. Autophagosome-like structures and several vacuole-enclosed lipid bodies were observed in postmeiotic tapetum cells specifically at the uninucleate stage during pollen development, which were completely abolished in a retrotransposon-insertional OsATG7 (autophagy-related 7)-knockout mutant defective in autophagy, suggesting that autophagy is induced in tapetum cells. Surprisingly, the mutant showed complete sporophytic male sterility, failed to accumulate lipidic and starch components in pollen grains at the flowering stage, showed reduced pollen germination activity, and had limited anther dehiscence. Lipidomic analyses suggested impairment of editing of phosphatidylcholines and lipid desaturation in the mutant during pollen maturation. These results indicate a critical involvement of autophagy in a reproductive developmental process of rice, and shed light on the novel autophagy-mediated regulation of lipid metabolism in eukaryotic cells. PMID:24674921

Kurusu, Takamitsu; Koyano, Tomoko; Hanamata, Shigeru; Kubo, Takahiko; Noguchi, Yuhei; Yagi, Chikako; Nagata, Noriko; Yamamoto, Takashi; Ohnishi, Takayuki; Okazaki, Yozo; Kitahata, Nobutaka; Ando, Daichi; Ishikawa, Masaya; Wada, Shinya; Miyao, Akio; Hirochika, Hirohiko; Shimada, Hiroaki; Makino, Amane; Saito, Kazuki; Ishida, Hiroyuki; Kinoshita, Tetsu; Kurata, Nori; Kuchitsu, Kazuyuki

2014-05-01

189

Construção e avaliação de um protótipo de máquina coletora de anteras / Construction and evaluation of an anther collector prototype machine  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Um protótipo de máquina coletora de anteras foi projetado e construído, e seu desempenho foi avaliado, comparando - se com o método de coleta manual, em flores rosáceas e campanuladas de pessegueiro (Prunus persica). O trabalho foi conduzido utilizando-se do delineamento experimental inteiramente ao [...] acaso, arranjado em um esquema bifatorial (2 métodos de remoção x 2 formas florais), com 12 repetições de 30 balões florais. O protótipo apresentou maior velocidade de processamento, sem diminuir a qualidade do pólen, mesmo sendo armazenadas anteras com maior quantidade de filetes e descartado maior número de anteras do que o método manual. Abstract in english An anther collector prototype machine was projected and built. Its performance was evaluated by comparisons between the use of the prototype and the traditional manual method, both for showy and non-showy peach-tree flowers (Prunus persica). The study was accomplished in August 2011 using a complete [...] ly randomized experimental design, arranged in a bi-factorial scheme (2 collection methods x 2 flower forms), with 12 repetitions, each consisted by 30 flowers. The prototype proved to be faster in the anther extraction time without losses in the pollen quality, even harvesting anthers with higher fillet amounts and discarding a higher quantity of anthers than the manual method.

Tonet, Rodrigo; Sachet, Marcos Robson; Citadin, Idemir; Modolo, Alcir José.

190

Construção e avaliação de um protótipo de máquina coletora de anteras Construction and evaluation of an anther collector prototype machine  

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Full Text Available Um protótipo de máquina coletora de anteras foi projetado e construído, e seu desempenho foi avaliado, comparando - se com o método de coleta manual, em flores rosáceas e campanuladas de pessegueiro (Prunus persica. O trabalho foi conduzido utilizando-se do delineamento experimental inteiramente ao acaso, arranjado em um esquema bifatorial (2 métodos de remoção x 2 formas florais, com 12 repetições de 30 balões florais. O protótipo apresentou maior velocidade de processamento, sem diminuir a qualidade do pólen, mesmo sendo armazenadas anteras com maior quantidade de filetes e descartado maior número de anteras do que o método manual.An anther collector prototype machine was projected and built. Its performance was evaluated by comparisons between the use of the prototype and the traditional manual method, both for showy and non-showy peach-tree flowers (Prunus persica. The study was accomplished in August 2011 using a completely randomized experimental design, arranged in a bi-factorial scheme (2 collection methods x 2 flower forms, with 12 repetitions, each consisted by 30 flowers. The prototype proved to be faster in the anther extraction time without losses in the pollen quality, even harvesting anthers with higher fillet amounts and discarding a higher quantity of anthers than the manual method.

Rodrigo Tonet

2013-03-01

191

Effects of antihypertensive drugs on alcohol-induced functional responses of cultured human endothelial cells.  

Science.gov (United States)

Alcohol-induced endothelial changes might contribute to an increase in blood pressure in regular alcohol consumers. Some antihypertensive drugs affect oxidative stress and endothelial function and might counteract the effects of alcohol at the cellular level. The aim of this study was to investigate in vitro the effects of three different types of antihypertensive agents on alcohol-induced endothelial responses and oxidative stress. Cultured human endothelial cells were exposed to increasing concentrations (1, 10, 60 micromol/L) of zofenoprilat, carvedilol, and lacidipine in the absence and in the presence of ethanol (140 mmol/L). Concentrations of endothelin (ET) and nitric oxide (NO) were measured in the culture media as markers of endothelial function, and malondialdehyde (MDA) and intracellular glutathione (GSHi) were measured as markers of oxidative stress. Exposure to alcohol increased the levels of ET, NO, and MDA, and decreased GSHi. Carvedilol and zofenoprilat were more effective than lacidipine in counteracting the effects of alcohol on ET production. Alcohol-induced NO production was enhanced by carvedilol, whereas zofenoprilat and lacidipine did not have a significant effect. The alcohol-induced increase in MDA concentrations was blunted by all three drugs, but only carvedilol restored a normal response. All three drugs increased GSHi levels, with the effect being greater for carvedilol and lacidipine than zofenoprilat. Carvedilol is more effective than zofenoprilat and lacidipine in counteracting alcohol-induced endothelial responses in vitro and in decreasing oxidative stress. These effects might be particularly beneficial in patients with alcohol-related hypertension. PMID:18360055

Soardo, Giorgio; Donnini, Debora; Moretti, Massimo; Milocco, Carla; Catena, Cristiana; Sechi, Leonardo A

2008-02-01

192

PRELIMINARY DATA OF THE IN VITRO CULTURE RESPONSE OF ROSA CANINA L. SPECIES  

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The in vitro cultures of Rosa canina L. were initiated starting from shoot tips harvested during various periods of the vegetative season. The first observations ascertained that the offshoots cut off at the beginning of July offred a bestin vitro response, and the MS medium supplemented with BAP (1.0 mg/l) and IBA (0.5 mg/l) induced both the multiple shooting and the formation of callus surrounding the shoots’ base. Some of the shoots provided roots on this mediumformula (spora...

Gogu Gheorghita; Daniela Nicuta; Diana-Elena Maftei; Ioan Daniel Maftei

2012-01-01

193

Transcription of storage protein genes in cultured Brassica napus embryos in response to exogenous abscisic acid  

International Nuclear Information System (INIS)

Two major seed storage proteins, cruciferin and napin, accumulate during embryogeny in Brassica napus. We are determining whether the levels of storage protein mRNAs in cultured embryos are controlled at the transcriptional level in response to ABA. The nuclei were isolated from the embryos and incubated in a transcription mix with 32P-GTP, and the incorporation into specific RNAs was determined by DNA excess filter hybridization. The transcription rate of cruciferin increased about 2-fold, and the transcription rate of napin increased about 3- to 4-fold in ABA-treated embryos compared to embryos cultured on basal medium. This increase in transcription rate is consistent with the increases in RNA levels which are seen in parallel experiments. In the same experiments, the transcription rates of actin and the rRNA genes were unaffected by ABA. In reinduction experiments, embryos which were switched from basal medium to medium containing ABA at 12 or 24 h showed an increase in transcription rate of the seed storage protein genes to the same level as those which were cultured on ABA at time 0

1986-01-01

194

Phenotypic stress response of Pseudomonas aeruginosa following culture in water microcosms.  

Science.gov (United States)

The purpose of the present study was to explore the potential behavioural changes of Pseudomonas aeruginosa following growth in different aquatic environmental conditions. To achieve this, P. aeruginosa was cultured in various water microcosms for 12 months under fixed (pH, nutrients and temperature) factors. P. aeruginosa responses to these conditions were investigated using colony morphotype, biochemical and enzymatic characterisation, pyocin typing, serotyping, sensitivity to different classes of antibiotics and molecular identification. Results show that starvation in water microcosms lead to unusual phenotypes. Of interest is that the pyocin changed from 24/n in the wild type to 83/a following culture in the water microcosms, and the serotype changed from O6 in the wild type to O1 in microcosm-cultured P. aeruginosa. Furthermore, the starvation period in various aquatic microcosms enhanced the resistance of P. aeruginosa against beta-lactam antibiotics. Compared to the other aquatic environments, the seawater microcosm produced the greatest amount of variations in P. aeruginosa. Overall, data demonstrated a high adaptability of P. aeruginosa to environmental changes. This may explain the unusual antibiotic-resistant phenotypes belonging to P. aeruginosa species, and their capacity for spreading that leads to human infections. PMID:22361708

Cheriaa, Jihane; Rouabhia, Mahmoud; Maatallah, Makaoui; Bakhrouf, Amina

2012-03-01

195

Effect of dexamethasone on the cytotoxic and enzymatic response of cultured endothelial cells to radiation  

International Nuclear Information System (INIS)

Experiments were conducted to determine (1) whether glucocorticoids directly protected endothelial cells (EC) from radiation and (2) if angiotensin converting enzyme (ACE) activity, known to be increased by glucocorticoid, played a role in the EC response to radiation. Confluent monolayers of EC cultured from bovine aorta EC were treated with dexamethasone (10-6 M); after irradiation (5.0 Gy, 60Co ?) ACE and lactate dehydrogenase (LDH) activities, DNA and protein contents, and nuclei number were measured. Combined dexamethasone treatment and radiation increased cellular ACE activity at a time when neither agent alone had an effect (24-hr dexamethasone exposure before 5 Gy and assayed 24 hr after 5 Gy). This interaction between radiation and dexamethasone treatment suggests that the glucocorticoid modifies the cell's response to injury. Although this interaction does not ameliorate radiation cytotoxicity, maintenance of ACE levels in injured vessels by hormones may have physiological significance in the hemodynamics of irradiated tissues

1985-01-01

196

Influence of Explant Source and Medium Ingredients on Culture Responses of Microsperma Lentil Cultivar Masoor-85  

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Full Text Available Culture responses of 9 lentil explants were compared in various media having different ingredients. The most promising were the scrapped axillary portions of basal nodes for enhanced regeneration. The optimum size of the explant was also determined. The callogenesis response varied with the explant and ranged between 0.3 - 0.5 cm. Among the sugars tested, sucrose was the best for callussing. Auxin 2,4-D induced callussing but cytokinin enhanced formation of shoot primordia in explants. Both BA and K promoted multiple shoot formation but K and GA gave more shoot buds. Cytokinins with auxins gave callussing. Callus was also induced in explants when grown in K (10 mg/l + GA (1mg/l containing medium in the dark. When callus was shifted to light it started regeneration as green dots. The addition of seed extract to K and GA medium considerably enhanced regenerations.

N. Altaf

1998-01-01

197

Responses in animals vaccinated with the Theileria annulata (Hisar) cell culture vaccine.  

Science.gov (United States)

Bovine tropical theileriosis caused by Theileria annulata is an economically important disease of cattle in India. The disease has assumed paramount importance with the intensification of cross-breeding programmes aimed at enhancing milk production in the country. To control this disease, a cell culture vaccine was developed in this department by continuous passaging of T. annulata (Hisar) schizonts in vitro. Current work in this department has concentrated on the epidemiology of theileriosis: development of the cell culture vaccine for very young calves and pregnant cows; evaluation of serological responses using immunofluorescent antibody (IFA) tests and Enzyme-linked immunosorbent antibody assays (ELISA); studies on the duration of immunity stimulated by the cell culture vaccine; the immune/susceptible status of calves born to vaccinated dams. Results have shown the following. Clinical cases of theileriosis were mainly observed in young calves below two months of age followed by adults in exotic and cross-bred animals. Amongst indigenous animals, only young calves below two months of age suffered from clinical disease. Clinical cases of theileriosis mainly occurred between the months of April to October. The T. annulata schizont cell culture vaccine developed in the department was extensively used in the susceptible calves and pregnant/lactating cows in the field. Sufficiently high antibody titres were detected by both schizont as well as piroplasm antigen using both ELISA and IFAT. The results indicated that the vaccine was safe, potent and effective for all breeds and age groups of cattle under field conditions. ELISA was standardised for T. annulata using three antigens, viz.: soluble piroplasm, soluble schizont and cellular schizont antigens. Comparison of results with IFAT showed that ELISA is more sensitive, objective, reliable and specific as well as less cumbersome than IFAT. Piroplasm, cellular schizont and soluble schizont antigens were found to be suitable for the detection of antitheilerial antibodies as per their order in ELISA. Studies on the duration of immunity stimulated by the T. annulata schizont cell culture vaccine indicated that immunity started waning after six months. Calves born of dams immunised against T. annulata with the cell culture vaccine were found to be fully susceptible to theileriosis soon after birth. This indicated that there was no passive transfer of immunity from dams to their offspring through colostrum. PMID:9512755

Beniwal, R K; Nichani, A K; Sharma, R D; Rakha, N K; Suri, D; Sarup, S

1997-11-01

198

GDNF elicits distinct immediate-early gene responses in cultured cortical and mesencephalic neurons.  

Science.gov (United States)

Glial cell line-derived neurotrophic factor (GDNF) has been recognized as a survival-promoting molecule for several neuronal populations in the central nervous system (CNS), including midbrain dopaminergic neurons and cortical neurons. Whereas it is well established that GDNF affects dopaminergic cell survival through a receptor complex composed of the tyrosine kinase, Ret, and the glycosylphosphatidylinositol (GPI)-anchored protein, GFRalpha-1, c-Ret is basically undetectable in cortical neurons. In the present study, we have compared GDNF signaling in cortical and mesencephalic neurons by using GDNF-induced expression of the immediate-early genes, c-fos and mgif, as a readout. We found that stimulation of embryonic day (E)17 cortical cultures for 3 hr with GDNF at concentrations ranging from 10 to 80 ng/ml did not result in detectable c-fos expression. In contrast, c-fos expression occurred in E14 mesencephalic cultures exposed to both low and high GDNF concentrations. Vice versa, cortical neurons responded to high GDNF concentrations (80 ng/ml) with an increase in mRNA encoding mGIF, while a similar mGIF response was absent in mesencephalic cultures. Cleavage of GFRalpha receptor subunits from their GPI anchors by phosphatidylinositol-specific phospholipase C (PIPLC) abolished GDNF-induced c-fos expression in mesencephalic cultures, but did not interfere with the effects of GDNF on cortical mgif expression. Together, these findings point to distinct differences in the GDNF recognition and/or signal transduction machinery of cortical and mesencephalic neurons. PMID:12548703

Pezeshki, Gita; Franke, Barbara; Engele, Jürgen

2003-02-15

199

Induction of heme oxygenase: A general response to oxidant stress in cultured mammalian cells  

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Accumulation of heme oxygenase mRNA is strongly stimulated by treatment of cultured human skin fibroblasts with ultraviolet radiation, hydrogen peroxide, or the sulfhydryl reagent sodium arsenite. Since this will result in a transient reduction in the prooxidant state of cells, the phenomenon may represent an important inducible antioxidant defense mechanism. To examine the generality of the response, we have measured the accumulation of the specific mRNA in a variety of human and mammalian cell types after inducing treatments. Induction by sodium arsenite is observed in all additional human cell types tested. This includes primary epidermal keratinocytes and lung and colon fibroblasts as well as established cell lines such as HeLa, TK6 lymphoblastoid, and transformed fetal keratinocytes. Strong induction of heme oxygenase mRNA is also observed following sodium arsenite treatment of cell lines of rat, hamster, mouse, monkey, and marsupial origin. The agents which lead to induction in cultured human skin fibroblasts fall into two categories: (a) those which are oxidants or can generate active intermediates (ultraviolet A radiation, hydrogen peroxide, menadione, and the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate); (b) agents which are known to interact with or modify cellular glutathione levels (buthionine sulfoximine, sodium arsenite, iodoacetamide, diamide, and cadmium chloride). These observations strongly support the hypothesis that induction of the enzyme is a general response to oxidant stress in mammalian cells and are consistent with the possibility that the cellular redox state plays a key role.

Applegate, L.A.; Luscher, P.; Tyrrell, R.M. (Swiss Institute for Experimental Cancer Research, Epalinges (Switzerland))

1991-02-01

200

Adriamycin response of two human tumor xenografts using a double-radiolabel organ culture method  

International Nuclear Information System (INIS)

A double-radiolabel method of quantitating drug response in a simple organ culture system was used to study the effects of adriamycin on two human tumor xenografts in vitro. Explants of X56, an adenocarcinoma of the colon, and HXG2, an amelanotic melanoma, both maintained by serial transplantation in athymic mice, were sequentially incubated in vitro with 14C-thymidine, one of several concentrations of adriamycin, and then 3H-thymidine. The ratios of second to first radiolabel incorporation declined as a function of adriamycin concentration. HXG2 was significantly more responsive to adriamycin than X56 in the double-radiolabelled assay. Greater sensitivity of HXG2 was confirmed by three additional methods: the human tumor stem cell assay (HTSCA), chemotherapy trials in tumor-bearing athymic mice, and a double-radiolabel protocol in vivo in tumor-bearing athymic mice. An organ culture method of this type may be useful in screening individual patients' tumors for drug resistance. (author). 2 figs., 1 tab., 15 refs

1989-01-01

 
 
 
 
201

Induction of heme oxygenase: A general response to oxidant stress in cultured mammalian cells  

International Nuclear Information System (INIS)

Accumulation of heme oxygenase mRNA is strongly stimulated by treatment of cultured human skin fibroblasts with ultraviolet radiation, hydrogen peroxide, or the sulfhydryl reagent sodium arsenite. Since this will result in a transient reduction in the prooxidant state of cells, the phenomenon may represent an important inducible antioxidant defense mechanism. To examine the generality of the response, we have measured the accumulation of the specific mRNA in a variety of human and mammalian cell types after inducing treatments. Induction by sodium arsenite is observed in all additional human cell types tested. This includes primary epidermal keratinocytes and lung and colon fibroblasts as well as established cell lines such as HeLa, TK6 lymphoblastoid, and transformed fetal keratinocytes. Strong induction of heme oxygenase mRNA is also observed following sodium arsenite treatment of cell lines of rat, hamster, mouse, monkey, and marsupial origin. The agents which lead to induction in cultured human skin fibroblasts fall into two categories: (a) those which are oxidants or can generate active intermediates (ultraviolet A radiation, hydrogen peroxide, menadione, and the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate); (b) agents which are known to interact with or modify cellular glutathione levels (buthionine sulfoximine, sodium arsenite, iodoacetamide, diamide, and cadmium chloride). These observations strongly support the hypothesis that induction of the enzyme is a general response to oxidant stress in mammalian cells and are consistent with the possibility that the cellular redox state plays a key role

1991-02-01

202

Ionizing radiation-induced adaptive response in human fibroblasts under 3-dimensional culture condition  

International Nuclear Information System (INIS)

Objective: To observe the adaptive response induced by ionizing radiation in human fibroblasts under 3-dimensional culture condition. Methods: Human fibroblasts were cultured under 3-D condition. Western blot was used to detect the expressions of p53 and p21. Immunofluorescence and confocal microscopy were used to detect the morphological changes. Results: The structures of the cells under 2-D and 3-D conditions were fundamentally different, the cells under 3-D condition stretched out and formed microspikes, the proportions of normal, abnormal and in between were 87.05%, 6.1% and 6.85%, respectively. After the treatment of 2 Gy(D2) most of the fibroblasts shrank and the microspikes disappeared, while the pre-treatment of 0.1 Gy(D1) pulsing the challenging dose of 2 Gy(i. e., D1 + D2) caused the decrease of abnormal cells and the increase of the normal cells and in between (35.5%:34.7%:30.4%). Conclusions: Under the 3-D conditions pretreatment with low dose radiation could attenuate the morphological changes induced by high dose. i. e. induced the adaptive response. (authors)

2007-06-01

203

Assessing the Impact of the National Cultural Framework on Responsible Corporate Behaviour towards Consumers: an Application of Geert Hofstede`s Cultural Model  

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Full Text Available This article aims to define and measure responsible corporate behaviour towards consumers in EU countries by defining an index of responsible corporate behaviour towards consumers and to establish the impact of Geert Hofstede's cultural dimensions on the responsible behaviour of organisations towards consumers. The index uses a specific measurement methodology based on three major components of responsible corporate behaviour towards customers and on content analysis of the Eurostat databases, the RAPEX 2012 Annual Report, the 2012-2013 Global Competitiveness Report and the Global Reporting Initiative database. We used the multifactorial regression and the Wald significance test to demonstrate that organisations operating in countries characterised by low power distance, individualism, femininity, tolerance of unknown and long-term orientation pay more attention to responsible corporate behaviour towards customers. The study highlights theoretical considerations that support the influence of the national cultural framework on responsible corporate behaviour towards consumers. The methodology for calculating the index of responsible corporate behaviour towards consumers can become a basis of analysis of responsible corporate behaviour towards local consumers or other stakeholders.

Cristina G?nescu

2014-02-01

204

Efficient transformation of Kalanchoe blossfeldiana and production of male-sterile plants by engineered anther ablation.  

Science.gov (United States)

Engineered male sterility in ornamental plants has many applications such as facilitate hybrid seed production, eliminate pollen allergens, reduce the need for deadheading to extend the flowering period, redirect resources from seeds to vegetative growth, increase flower longevity and prevent gene flow between genetically modified and related native plants. We have developed a reliable and efficient Agrobacterium-mediated protocol for the genetic transformation of different Kalanchoe blossfeldiana commercial cultivars. Transformation efficiency for cv. 'Hillary' was 55.3% whereas that of cv. 'Tenorio' reached 75.8%. Selection was carried out with the nptII gene and increasing the kanamycin concentration from 25 to 100 mg l(-1) allowed to reduced escapes from 50 to 60% to virtually 0%. This method was used to produce male-sterile plants through engineered anther ablation. In our approach, we tested a male sterility chimaeric gene construct (PsEND1::barnase) to evaluate its effectiveness and effect on phenotype. No significant differences were found in the growth patterns between the transgenic lines and the wild-type plants. No viable pollen grains were observed in the ablated anthers of any of the lines carrying the PsEND1::barnase construct, indicating that the male sterility was complete. In addition, seed set was completely abolished in all the transgenic plants obtained. Our engineered male-sterile approach could be used, alone or in combination with a female-sterility system, to reduce the invasive potential of new ornamentals, which has become an important environmental problem in many countries. PMID:19921199

García-Sogo, Begoña; Pineda, Benito; Castelblanque, Lourdes; Antón, Teresa; Medina, Mónica; Roque, Edelín; Torresi, Claudia; Beltrán, José Pío; Moreno, Vicente; Cañas, Luis Antonio

2010-01-01

205

Studies in tissue culture of some indigenous rice (Oryza glaberrima Steud.) accessions in Ghana  

International Nuclear Information System (INIS)

A study was conducted with the aim of developing separate protocols for callus induction and plant regeneration from different parts of three O. glaberrima accessions indigenous to Ghana. The three O. glaberrima accessions, Guame, N/4 and SARI 1 were assessed for their callus induction and plant regeneration ability from leaf segments, mature dehusked seeds and anthers on different concentrations of plant growth regulators, incorporated into Murashige and Skoog, (1962) (MS) basal medium. For leaf segments, callus was induced on MS supplemented with (0-10) mg/l 2,4-D. Callus induction frequency was significantly (p?0.05) different among accessions, as well as among the 2,4-dichlorophenoxyacetic acid (2,4-D) levels tested. Highest callus induction frequency was exhibited at a concentration of 6 mg/l 2,4-D for all accessions tested. Callus obtained was sub-cultured on regeneration medium consisting of MS supplemented with (1:0-5) mg.l NAA:BAP. Plant regeneration was nil. Instead, prolific root formation was observed. For mature dehusked seeds, callus induction medium consisted of MS supplemented with (0-6) mg/l 2,4-D. All tested accessions exhibited highest callus frequency at 4 mg/l 2,4-D. Similarly callus induction frequency was significantly (p?0.05) different among accessions, as well as among concentrations of 2,4-D tested. Calli obtained were sub-cultured on MS medium supplemented with (0-2.5) mg/l 6-benzylaminopurine (BAP) and exhibited the highest regeneration frequency on medium containing 2.0 mg/l BAP. However, callus induced on a concentration of 3 mg/l 2,4-D and sub-cultured on a concentration of 2 mg/l BAP gave the best response n terms of shoot proliferation, growth and root development and therefore were considered to be the optimum concentrations for callus induction and plant regeneration respectively. Plantlet regeneration was achieved only in accession N/4 while Guame and SARI 1 exhibited poor regeneration response. Among the three rice accessions evaluated, N/4 was the most promising accession in terms of callus induction frequency and regeneration ability. The three accessions of O. glaberrima were again studied for their response to anther culture in terms of callus induction and frequency of plant regeneration using N, Garfish and D oy, MS and Nis tch tissue culture media, and supplemented with 2,4-D (1:(0-5) mg/l) were used for callus induction. No response to callus formation was obtained after 16 weeks of culture and a conclusion was drawn that all three accessions were recalcitrant to anther culture. (au)

2011-01-01

206

Characterization of callase (?-1,3-D-glucanase) activity during microsporogenesis in the sterile anthers of Allium sativum L. and the fertile anthers of A. atropurpureum.  

Science.gov (United States)

We examined callase activity in anthers of sterile Allium sativum (garlic) and fertile Allium atropurpureum. In A. sativum, a species that produces sterile pollen and propagates only vegetatively, callase was extracted from the thick walls of A. sativum microspore tetrads exhibited maximum activity at pH 4.8, and the corresponding in vivo values ranged from 4.5 to 5.0. Once microspores were released, in vitro callase activity peaked at three distinct pH values, reflecting the presence of three callase isoforms. One isoform, which was previously identified in the tetrad stage, displayed maximum activity at pH 4.8, and the remaining two isoforms, which were novel, were most active at pH 6.0 and 7.3. The corresponding in vivo values ranged from pH 4.75 to 6.0. In contrast, in A. atropurpureum, a sexually propagating species, three callase isoforms, active at pH 4.8-5.2, 6.1, and 7.3, were identified in samples of microsporangia that had released their microspores. The corresponding in vivo value for this plant was 5.9. The callose wall persists around A. sativum meiotic cells, whereas only one callase isoform, with an optimum activity of pH 4.8, is active in the acidic environment of the microsporangium. However, this isoform is degraded when the pH rises to 6.0 and two other callase isoforms, maximally active at pH 6.0 and 7.3, appear. Thus, factors that alter the pH of the microsporangium may indirectly affect the male gametophyte development by modulating the activity of callase and thereby regulating the degradation of the callose wall. PMID:22438078

Winiarczyk, Krystyna; Jaroszuk-?cise?, Jolanta; Kupisz, Kamila

2012-06-01

207

Determination of dose- response relationship in cultured human by lymphocytes for biological dosimetry  

International Nuclear Information System (INIS)

Background: lymphocyte- dicentric assay is the most generally accepted method for biological dosimetry of overexposed individuals. In this study, the frequency of unstable chromosome aberration in blood lymphocytes was used to estimate radiation dose received by individuals. Evaluation of dose using a calibration curve produced elsewhere may have a significant uncertainty; therefore, experiments were performed to produce a dose-response curve using an established protocol of international atomic energy agency. Materials and methods: lymphocytes in whole peripheral blood obtained from healthy individuals, were exposed to various doses of gamma radiation (0.25-4 Gy). Then after 1 hour of incubation in 37digC , were cultured in complete RPMI-1640 medium. 500 mitoses were analyzed for the presence or absence of unstable chromosomal aberrations for each radiation dose after the standard metaphase preparation and staining slides. Results and conclusion: Intercellular distribution chromosomes at each radiation dose has been used to contrast a dose- response curve. It seems that dose-effect relationship follows with the linear-quadratic model. There is a good agreement between our dose- response curves with similar published studies by other laboratories

2004-09-01

208

Morphological development of anthers induced by the dimorphic smut fungus Microbotryum violaceum in female flowers of the dioecious plant Silene latifolia.  

Science.gov (United States)

When inoculated with the dimorphic smut fungus Microbotryum violaceum (Pers.) G. Deml and Oberwinkler, the female flower of the dioecious plant Silene latifolia (Miller) E.H.L. Krause develops anther-like structures filled with spores instead of pollen grains. Using natural scanning electron microscopy, Nomarski interference microscopy, and fluorescence microscopy, we investigated the morphological modifications of the host plant resulting from this parasitism and the localization of smut hyphae in the flower bud. Flowers of infected plants lasted significantly longer than those of healthy plants, probably because the infection strengthened floral organs, such as the flower base and the anther filaments. Smut hyphae were observed throughout all organs of the young flower buds of infected plants, including sepals, petals, stamens, and pistil primordia. In healthy female flowers, anthers initiated sporogenous cell formation, but lacked parietal cell layers. By contrast, the parietal cell layers of infected female flowers differentiated into tapetal tissue, middle cell layers, and endothecial layers, as in the anthers of healthy male flowers. Smut spore formation in the infected anther was initiated in intercellular regions between the sporogenous cells, resulting in degeneration of premature sporogenous cells, tapetal tissue, and middle cell layers. The development of the endothecial layers and epidermis in the infected anther were morphologically normal. PMID:14551772

Uchida, Wakana; Matsunaga, Sachihiro; Sugiyama, Ryuji; Kazama, Yusuke; Kawano, Shigeyuki

2003-12-01

209

Marker expression, behaviors, and responses vary in different lines of conditionally immortalized cultured podocytes.  

Science.gov (United States)

The state-of-the-art cultured podocyte is conditionally immortalized by expression of a temperature-sensitive mutant of the SV40 large-T antigen. These cultures proliferate at 33°C and differentiate at 37°C into arborized cells that more closely resemble in vivo podocytes. However, the degree of resemblance remains controversial. In this study, several parameters were measured in podocyte cell lines derived from mouse (JR, KE), human (MS), and rat (HK). In all lines, the quantities of NEPH1 and podocin proteins and NEPH1 and SYNPO mRNAs were comparable to glomeruli, while synaptopodin and nephrin proteins and NPHS1 and NPHS2 mRNAs were KE, and of doxorubicin was JR ? KE > MS, while HK cells were almost unaffected. Process formation was largely a result of contractile action after formation of lamellipodia. These findings demonstrate dramatic differences in marker expression, response to toxins, and motility between lines of podocytes from different species and even between similarly-derived mouse lines. PMID:21632959

Chittiprol, Seetharamaiah; Chen, Phylip; Petrovic-Djergovic, Danica; Eichler, Tad; Ransom, Richard F

2011-09-01

210

Development of Growth Medium for Centella Asiatica Cell Culture Via Response Surface Methodology  

Directory of Open Access Journals (Sweden)

Full Text Available The effects of sucrose, Indole-3-Acetic Acid (IAA and 6-BenzylAminoPurine (BAP concentrations on cell growth of Centella asiatica cell suspension culture were studied. The concentrations were designed using Central-composite experimental design and regression analysis was carried out to obtain response surface model describing cell growth for prediction of optimum conditions. Only sucrose as a single factor was positively significant for cell growth. Increasing sucrose concentration from 3.32 to 6.68% (w/v resulted in an increase in dry cell weight from 16-27 g L-1. IAA and BAP as single factors and other possible interaction effect were insignificant. The optimum values predicted to be 6.68% (w/v sucrose, 0.84 mg L-1 IAA and 1.17 mg L-1 BAP yielding 27.4 g L-1 dry cell weight with 81.4% regression equation fitness of the experimental data.

Rozita Omar

2004-01-01

211

PRELIMINARY DATA OF THE IN VITRO CULTURE RESPONSE OF ROSA CANINA L. SPECIES  

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Full Text Available The in vitro cultures of Rosa canina L. were initiated starting from shoot tips harvested during various periods of the vegetative season. The first observations ascertained that the offshoots cut off at the beginning of July offred a bestin vitro response, and the MS medium supplemented with BAP (1.0 mg/l and IBA (0.5 mg/l induced both the multiple shooting and the formation of callus surrounding the shoots’ base. Some of the shoots provided roots on this mediumformula (sporadically. The hormone-free MS medium stimulated the rooting of the shoots, and scarcely the production of callus at the stem base. The future tests aim to fiind out the best medium variants to enhance the direct caulogenesis,the rooting of the in vitro shoots, and the survival of the regenerants during the ex vitro environment.

Ioan Daniel Maftei

2012-06-01

212

Response to Dengue virus infections altered by cytokine-like substances from mosquito cell cultures  

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Full Text Available Abstract Background With both shrimp and commercial insects such as honey bees, it is known that stable, persistent viral infections characterized by absence of disease can sometimes shift to overt disease states as a result of various stress triggers and that this can result in serious economic losses. The main research interest of our group is to understand the dynamics of stable viral infections in shrimp and how they can be destabilized by stress. Since there are no continuous cell lines for crustaceans, we have used a C6/36 mosquito cell line infected with Dengue virus to test hypotheses regarding these interactions. As a result, we accidentally discovered two new cytokine-like substances in 5 kDa extracts from supernatant solutions of acutely and persistently infected mosquito cells. Results Na?ve C6/36 cells were exposed for 48 h to 5 kDa membrane filtrates prepared from the supernatant medium of stable C6/36 mosquito cell cultures persistently-infected with Dengue virus. Subsequent challenge of naïve cells with a virulent stock of Dengue virus 2 (DEN-2 and analysis by confocal immunofluorescence microscopy using anti-DEN-2 antibody revealed a dramatic reduction in the percentage of DEN-2 infected cells when compared to control cells. Similar filtrates prepared from C6/36 cells with acute DEN-2 infections were used to treat stable C6/36 mosquito cell cultures persistently-infected with Dengue virus. Confocal immunofluorescence microscopy revealed destabilization in the form of an apoptosis-like response. Proteinase K treatment removed the cell-altering activities indicating that they were caused by small polypeptides similar to those previously reported from insects. Conclusions This is the first report of cytokine-like substances that can alter the responses of mosquito cells to Dengue virus. This simple model system allows detailed molecular studies on insect cytokine production and on cytokine activity in a standard insect cell line.

Laosutthipong Chaowanee

2010-11-01

213

A refined in vitro model to study inflammatory responses in organotypic membrane culture of postnatal rat hippocampal slices  

Science.gov (United States)

Background Propagated tissue degeneration, especially during aging, has been shown to be enhanced through potentiation of innate immune responses. Neurodegenerative diseases and a wide variety of inflammatory conditions are linked together and several anti-inflammatory compounds considered as having therapeutic potential for example in Alzheimer's disease (AD). In vitro brain slice techniques have been widely used to unravel the complexity of neuroinflammation, but rarely, has the power of the model itself been reported. Our aim was to gain a more detailed insight and understanding of the behaviour of hippocampus tissue slices in serum-free, interface culture per se and after exposure to different pro- and anti-inflammatory compounds. Methods The responses of the slices to pro- and anti-inflammatory stimuli were monitored at various time points by measuring the leakage of lactate dehydrogenase (LDH) and the release of cytokines interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-?) and nitric oxide (NO) from the culture media. Histological methods were applied to reveal the morphological status after exposure to stimuli and during the time course of the culture period. Statistical power analysis were made with nQuery Advisor®, version 5.0, (Statistical Solutions, Saugus, MA) computer program for Wilcoxon (Mann-Whitney) rank-sum test. Results By using the interface membrane culture technique, the hippocampal slices largely recover from the trauma caused by cutting after 4–5 days in vitro. Furthermore, the cultures remain stable and retain their responsiveness to inflammatory stimuli for at least 3 weeks. During this time period, cultures are susceptible to modification by inflammatory stimuli as assessed by quantitative biochemical assays and morphological characterizations. Conclusion The present report outlines the techniques for studying immune responses using a serum-free slice culture model. Statistically powerful data under controlled culture conditions and with ethically justified use of animals can be obtained as soon as after 4–5 DIV. The model is most probably suitable also for studies of chronic inflammation.

Huuskonen, Jari; Suuronen, Tiina; Miettinen, Riitta; van Groen, Thomas; Salminen, Antero

2005-01-01

214

The Evaluation of Response to Isolated Microspores Culture in Some Iranian Hexaploid Wheat (Triticum aestivum L.) Cultivars  

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The most important method of haploid plant production is isolated microspores culture. To be successful in this method, genetic potential of cultivars is very important. In this research, ten Iranian hexaploid wheat cultivars (exclusive of MV17) on the basis of their characters such as heat, drought and salinity resistant have been selected and their responses to isolated microspore culture were evaluated. Meanwhile the effects of two pretreatments (cold and heat + chemical) and embryo ind...

Mohammad Javad Ekhveh; Ahmad Moieni; Mokhtar Jalali Javaran

2013-01-01

215

Upregulation of the AT-hook DNA binding gene BoMF2 in OguCMS anthers of Brassica oleracea suggests that it encodes a transcriptional regulatory factor for anther development.  

Science.gov (United States)

Ogura cytoplasmic male sterility (OguCMS) is the most important CMS system used for F1 hybrid cabbage production worldwide. The anther abortion and defective pollen development exhibited in OguCMS are coordinately regulated by the mitochondrial male sterile gene orf138 and many nuclear transcriptional regulatory factors. AT-hook DNA binding proteins regulate cell-specific gene expression. In this study, we cloned the gene encoding the AT-hook DNA binding protein BoMF2 using the cDNA-AFLP TDF sequence, which was upregulated in OguCMS cabbage flower buds, as a querying probe. BoMF2 contains a 783-nt continuous complete open reading frame encoding a 260 amino-acid polypeptide. In vivo transient expression assays using GFP fusions showed that BoMF2 protein was located in the nucleus. BoMF2 was preferentially expressed in cabbage stamens, with a short expression window at anther development stage 7-8. However, in OguCMS flowers, BoMF2 expression continued into the mature pollen stage and was concomitant with the continued proliferation of tapetum cells exhibited in this mutant. Arabidopsis plants overexpressing BoMF2 showed significantly shorter siliques than the wild type, as well as decrease of pollen viability. These results suggest that BoMF2, a transcriptional regulatory factor, might regulate tapetum proliferation during anther development. PMID:24443226

Kang, Jungen; Guo, Yingying; Chen, Yujuan; Li, Hailong; Zhang, Lei; Liu, Haixia

2014-04-01

216

Development and use of culture systems to modulate specific cell responses  

Science.gov (United States)

Culture surfaces that induce specific localized cell responses are required to achieve tissue-like cell growth in three-dimensional (3D) environments, as well as to develop more efficient cell-based diagnostic techniques, noticeably when working with fragile cells such as stem cells or platelets. As such, Chapter 1 of this thesis work is devoted to the review of 3D cell-material interactions in vitro and the corresponding existing culture systems available to achieve in vivo-like cell responses. More adequate 3D culture systems will need to be developed to mimic several characteristics of in vivo environments, including lowered non-specific cell-material interactions and localized biochemical signaling. The experimental work in this thesis is based on the hypothesis that well-studied and optimized surface treatments will be able to lower non-specific cell-material interactions and allow local chemical modification in order to achieve specific localized cell-material interactions for different applications. As such, in Chapter 2 and Chapter 3 of this thesis, surface treatments were developed using plasma polymerization and covalent immobilization of a low-fouling polymer (i.e., poly(ethylene glycol)) and characterized and optimized using a large number of techniques including atomic force microscopy, quartz crystal microbalance, surface plasmon resonance, x-ray photoelectron spectroscopy and fluorescence-based techniques. The main plasma polymerization parameter important for surface chemical content, specifically nitrogen to carbon content, was identified as being glow discharge power, while reaction time and power determined plasma film thickness. Moreover, plasma films were shown to be stable in aqueous environments. Covalently-bound poly(ethylene glycol) (PEG) layers physicochemical and mechanical properties are dependent on fabrication methods. Polymer concentration in solution is an important indicator of final layer properties, and use of a theta solvent induces complex aggregation phenomena in solution yielding layers with widely different properties. Chemically available primary amine groups are also shown to be present, paving the way for the immobilization of bio-active molecules. An application of low-fouling locally modified surfaces is given in Chapter 4 by the development of a novel diagnostic surface to evaluate platelet activation which is until now very difficult as platelets are readily activated by in vitro manipulations. Significant results from volunteer donors indicate that this diagnostic instrument has the potential to allow the rapid estimation of platelet activation levels in whole blood.

Martin, Yves

217

The presence of a culturally similar or dissimilar social partner affects neural responses to emotional stimuli  

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Full Text Available Background: Emotional responding is sensitive to social context; however, little emphasis has been placed on the mechanisms by which social context effects changes in emotional responding. Objective: We aimed to investigate the effects of social context on neural responses to emotional stimuli to inform on the mechanisms underpinning context-linked changes in emotional responding. Design: We measured event-related potential (ERP components known to index specific emotion processes and self-reports of explicit emotion regulation strategies and emotional arousal. Female Chinese university students observed positive, negative, and neutral photographs, whilst alone or accompanied by a culturally similar (Chinese or dissimilar researcher (British. Results: There was a reduction in the positive versus neutral differential N1 amplitude (indexing attentional capture by positive stimuli in the dissimilar relative to alone context. In this context, there was also a corresponding increase in amplitude of a frontal late positive potential (LPP component (indexing engagement of cognitive control resources. In the similar relative to alone context, these effects on differential N1 and frontal LPP amplitudes were less pronounced, but there was an additional decrease in the amplitude of a parietal LPP component (indexing motivational relevance in response to positive stimuli. In response to negative stimuli, the differential N1 component was increased in the similar relative to dissimilar and alone (trend context. Conclusion: These data suggest that neural processes engaged in response to emotional stimuli are modulated by social context. Possible mechanisms for the social-context-linked changes in attentional capture by emotional stimuli include a context-directed modulation of the focus of attention, or an altered interpretation of the emotional stimuli based on additional information proportioned by the context.

Kate A. Woodcock

2013-06-01

218

Culture & Advertising : How masculinity or femininity of a culture is influencing the consumers’ responses on the gender appearance in advertisements?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Everybody has seen advertisements in his/her life even if this person is never watching television or listening to radio. However, an average person watches television 1 to 4 hours per day. In these hours of watching television, there is a big probability that this person will see an advertisement. But how does he/she react to this advertisement? There are probabilities of reacting positively or negatively or indifferently. Culture is one of the significant aspects that can determine the reac...

Sadek-endrawes, Marlin

2008-01-01

219

Male-fertility genes expressed in male flower buds of Silene latifolia include homologs of anther-specific genes.  

Science.gov (United States)

When the female plant of Silene latifolia is infected with the smut fungus Microbotryum violaceum, its rudimentary stamens develop into anthers which contain fungus teliospores instead of pollen. To identify genes required for maturation of anthers in S. latifolia, we performed a cDNA subtraction approach with healthy male buds and female buds infected with M. violaceum. We isolated five cDNA clones, which were preferentially expressed in healthy male buds during stages associated with a burst in tapetal activity. These five cDNAs are predicted to encode a mandelonitrile lyase protein (SlMDL1), a strictosidine synthase protein (SlSs), a glycosyl hydrolase 17 protein (SlGh17), a proline-rich protein APG precursor (SlAPG), and a chalcone-synthase-like protein (SlChs). All five genes showed expression in both healthy and fungus-infected male buds, but not expressed in either healthy or infected female buds. The first three genes were highly expressed in both tapetum and pollen grains while the last two genes were expressed only inside the tapetum of male flower buds. Phylogenetic analysis results showed that SlChs and SlGh17 belong to anther-specific subgroups of chalcone-synthase-like genes and glycosyl hydrolase 17 family genes, respectively. Our results suggest that the isolated five genes are related to the fertility of the anther leading to the development of fertile pollen. The smut fungus was not able to induce the expression of the five genes in the infected female buds. This raises the possibility that these genes are under the control of master gene(s) on the Y chromosome. PMID:16501309

Ageez, Amr; Kazama, Yusuke; Sugiyama, Ryuji; Kawano, Shigeyuki

2005-12-01

220

Anther Cap Retention Prevents Self-pollination by Elaterid Beetles in the South African Orchid Eulophia foliosa  

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• Background and Aims Pollination by insects that spend long periods visiting many flowers on a plant may impose a higher risk of facilitated self-pollination. Orchids and asclepiads are particularly at risk as their pollen is packaged as pollinia and so can be deposited on self-stigmas en masse. Many orchids and asclepiads have adaptations to limit self-deposition of pollinia, including gradual reconfiguration of pollinaria following removal. Here an unusual mechanism—anther cap retentio...

2006-01-01

 
 
 
 
221

Proteome Analysis of the Wild and YX-1 Male Sterile Mutant Anthers of Wolfberry (Lycium barbarum L.)  

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Pollen development is disturbed in the early tetrad stage of the YX-1 male sterile mutant of wolfberry (Lycium barbarum L.). The present study aimed to identify differentially expressed anther proteins and to reveal their possible roles in pollen development and male sterility. To address this question, the proteomes of the wild-type (WT) and YX-1 mutant were compared. Approximately 1760 protein spots on two-dimensional differential gel electrophoresis (2D-DIGE) gels were detected. A number o...

Zheng, Rui; Sijun Yue; Xu, Xiaoyan; Liu, Jianyu; Xu, Qing; Wang, Xiaolin; Han, Lu; Yu, Deyue

2012-01-01

222

Isolation and characterization of CaMF3, an anther-specific gene in Capsicum annuum L.  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Previous work on gene expression analysis based on RNA sequencing identified a variety of differentially expressed cDNA fragments in the genic male sterile-fertile line 114AB of Capsicum annuum L. In this work, we examined the accumulation of one of the transcript-derived fragments (TDFs), CaMF3 (ma [...] le fertile 3), in the flower buds of a fertile line. The full genomic DNA sequence of CaMF3 was 1,951 bp long and contained 6 exons and 5 introns, with the complete sequence encoding a putative 25.89 kDa protein of 234 amino acids. The predicted protein of CaMF3 shared sequence similarity with members of the isoamyl acetate-hydrolyzing esterase (IAH1) protein family. CaMF3 expression was detected only in flower buds at stages 7 and 8 and in open flowers of a male fertile line; no expression was observed in any organs of a male sterile line. Fine expression analysis revealed that CaMF3 was expressed specifically in anthers of the fertile line. These results suggest that CaMF3 is an anther-specific gene that may be essential for anther or pollen development in C. annuum.

Xuefeng, Hao; Changming, Chen; Guoju, Chen; Bihao, Cao; Qinghua, Chen; Jianjun, Lei.

223

Physiological responses of chemostat cultures of Aspergillus niger (B1-D) to simulated and actual oxidative stress.  

Science.gov (United States)

The physiological responses of chemostat cultures of the filamentous fungus, Aspergillus niger (B1-D) to simulated and actual oxidative stress, imposed respectively by addition of exogenous menadione (MD; a superoxide radical generating reagent) and gassing the culture with oxygen enriched air (25%, 50%, 75%, and 100% [v/v]), were examined. Changes in the levels of intracellular superoxide anions and defensive enzyme activities, such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), were monitored, together with glutathione and respiratory activity in both the dynamic phase and when a new steady state was established. Culture response to MD addition was distinct from that upon exposure to enriched oxygen conditions, in that MD caused elevated levels of intracellular protein, whereas oxygen enrichment caused reduced protein content, especially at low dilution rates. An unexpectedly low level of superoxide radical was found in oxygen-enriched steady-state cultures (>/=50%) at a range of dilution rates, which was not caused by elevated SOD activity. Under these conditions, it was noted that the ratio of rotenone-insensitive/total respiration increased, suggesting increased activity of the alternative respiratory pathway. This may have had the effect of reducing the endogenous generation of superoxide radicals under oxygen rich conditions, but also may have reduced the ATP yield due to the non-proton-pumping nature of the alternative respiratory pathway. Thus, the negative culture effects noted in many studies at high oxygen levels may not simply be due to elevated endogenous superoxide generation, but could be in part due to the consequences of metabolic changes in the culture that seek to minimize superoxide generation. The dynamic culture response was characterized by rapid elevation of intracellular superoxide anions and associated protective enzymes, especially SOD, and was clearly distinct from the adaptive response just described. PMID:12673769

Bai, Zhonghu; Harvey, Linda M; McNeil, Brian

2003-06-20

224

Dose–response analysis of phthalate effects on gene expression in rat whole embryo culture  

Energy Technology Data Exchange (ETDEWEB)

The rat postimplantation whole embryo culture (WEC) model serves as a potential screening tool for developmental toxicity. In this model, cultured rat embryos are exposed during early embryogenesis and evaluated for morphological effects. The integration of molecular-based markers may lead to improved objectivity, sensitivity and predictability of WEC in assessing developmental toxic properties of compounds. In this study, we investigated the concentration-dependent effects of two phthalates differing in potency, mono(2-ethylhexyl) phthalate (MEHP) and monomethyl phthalate (MMP, less toxic), on the transcriptome in WEC to examine gene expression in relation with dysmorphogenesis. MEHP was more potent than MMP in inducing gene expression changes as well as changes on morphology. MEHP induced significant enrichment of cholesterol/lipid/steroid (CLS) metabolism and apoptosis pathways which was associated with developmental toxicity. Regulation of genes within CLS metabolism pathways represented the most sensitive markers of MEHP exposure, more sensitive than classical morphological endpoints. As shown in direct comparisons with toxicogenomic in vivo studies, alterations in the regulation of CLS metabolism pathways has been previously identified to be associated with developmental toxicity due to phthalate exposure in utero. Our results support the application of WEC as a model to examine relative phthalate potency through gene expression and morphological responses. Additionally, our results further define the applicability domain of the WEC model for developmental toxicological investigations. -- Highlights: ? We examine the effect of two phthalates on gene expression and morphology in WEC. ? MEHP is more potent than MMP in inducing gene expression changes and dysmorphogenesis. ? MEHP significantly disrupts cholesterol metabolism pathways in a dose-dependent manner. ? Specific phthalate-related mechanisms in WEC are relevant to mechanisms in vivo.

Robinson, Joshua F. [National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Department of Toxicogenomics, Maastricht University, Maastricht (Netherlands); Verhoef, Aart; Beelen, Vincent A. van; Pennings, Jeroen L.A. [National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Piersma, Aldert H., E-mail: aldert.piersma@rivm.nl [National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht (Netherlands)

2012-10-01

225

Dynamic culture substrate that captures a specific extracellular matrix protein in response to light  

Energy Technology Data Exchange (ETDEWEB)

The development of methods for the off-on switching of immobilization or presentation of cell-adhesive peptides and proteins during cell culture is important because such surfaces are useful for the analysis of the dynamic processes of cell adhesion and migration. This paper describes a chemically functionalized gold substrate that captures a genetically tagged extracellular matrix protein in response to light. The substrate was composed of mixed self-assembled monolayers (SAMs) of three disulfide compounds containing (i) a photocleavable poly(ethylene glycol) (PEG), (ii) nitrilotriacetic acid (NTA) and (iii) hepta(ethylene glycol) (EG{sub 7}). Although the NTA group has an intrinsic high affinity for oligohistidine tag (His-tag) sequences in its Ni{sup 2+}-ion complex, the interaction was suppressed by the steric hindrance of coexisting PEG on the substrate surface. Upon photoirradiation of the substrate to release the PEG chain from the surface, this interaction became possible and hence the protein was captured at the irradiated regions, while keeping the non-specific adsorption of non-His-tagged proteins blocked by the EG{sub 7} underbrush. In this way, we selectively immobilized a His-tagged fibronectin fragment (FNIII{sub 7-10}) to the irradiated regions. In contrast, when bovine serum albumin-a major serum protein-was added as a non-His-tagged protein, the surface did not permit its capture, with or without irradiation. In agreement with these results, cells were selectively attached to the irradiated patterns only when a His-tagged FNIII{sub 7-10} was added to the medium. These results indicate that the present method is useful for studying the cellular behavior on the specific extracellular matrix protein in cell-culturing environments.

Nakanishi, Jun; Nakayama, Hidekazu; Horiike, Yasuhiro [World Premier International (WPI) Research Center Initiative, International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science - NIMS (Japan); Yamaguchi, Kazuo [Department of Chemistry, Faculty of Science and Research Institute for Photofunctionalized Materials, Kanagawa University (Japan); Garcia, Andres J, E-mail: NAKANISHI.Jun@nims.go.jp [Institute for Bioengineering and Bioscience, Woodruff School of Mechanical Engineering, Georgia Institute of Technology (United States)

2011-08-15

226

Dynamic culture substrate that captures a specific extracellular matrix protein in response to light  

International Nuclear Information System (INIS)

The development of methods for the off-on switching of immobilization or presentation of cell-adhesive peptides and proteins during cell culture is important because such surfaces are useful for the analysis of the dynamic processes of cell adhesion and migration. This paper describes a chemically functionalized gold substrate that captures a genetically tagged extracellular matrix protein in response to light. The substrate was composed of mixed self-assembled monolayers (SAMs) of three disulfide compounds containing (i) a photocleavable poly(ethylene glycol) (PEG), (ii) nitrilotriacetic acid (NTA) and (iii) hepta(ethylene glycol) (EG7). Although the NTA group has an intrinsic high affinity for oligohistidine tag (His-tag) sequences in its Ni2+-ion complex, the interaction was suppressed by the steric hindrance of coexisting PEG on the substrate surface. Upon photoirradiation of the substrate to release the PEG chain from the surface, this interaction became possible and hence the protein was captured at the irradiated regions, while keeping the non-specific adsorption of non-His-tagged proteins blocked by the EG7 underbrush. In this way, we selectively immobilized a His-tagged fibronectin fragment (FNIII7-10) to the irradiated regions. In contrast, when bovine serum albumin-a major serum protein-was added as a non-His-tagged protein, the surface did not permit its capture, with or without irradiation. In agreement with these results, cells were selectively attached to the irradiated patterns only when a His-tagged FNIII7-10 was added to the medium. These results indicate that the present method is useful for studying the cellular behavior on the specific extracellular matrix protein in cell-culturing environments.

2011-08-01

227

Dynamic culture substrate that captures a specific extracellular matrix protein in response to light  

Directory of Open Access Journals (Sweden)

Full Text Available The development of methods for the off–on switching of immobilization or presentation of cell-adhesive peptides and proteins during cell culture is important because such surfaces are useful for the analysis of the dynamic processes of cell adhesion and migration. This paper describes a chemically functionalized gold substrate that captures a genetically tagged extracellular matrix protein in response to light. The substrate was composed of mixed self-assembled monolayers (SAMs of three disulfide compounds containing (i a photocleavable poly(ethylene glycol (PEG, (ii nitrilotriacetic acid (NTA and (iii hepta(ethylene glycol (EG7. Although the NTA group has an intrinsic high affinity for oligohistidine tag (His-tag sequences in its Ni2+-ion complex, the interaction was suppressed by the steric hindrance of coexisting PEG on the substrate surface. Upon photoirradiation of the substrate to release the PEG chain from the surface, this interaction became possible and hence the protein was captured at the irradiated regions, while keeping the non-specific adsorption of non-His-tagged proteins blocked by the EG7 underbrush. In this way, we selectively immobilized a His-tagged fibronectin fragment (FNIII7–10 to the irradiated regions. In contrast, when bovine serum albumin—a major serum protein—was added as a non-His-tagged protein, the surface did not permit its capture, with or without irradiation. In agreement with these results, cells were selectively attached to the irradiated patterns only when a His-tagged FNIII7-10 was added to the medium. These results indicate that the present method is useful for studying the cellular behavior on the specific extracellular matrix protein in cell-culturing environments.

Jun Nakanishi, Hidekazu Nakayama, Kazuo Yamaguchi, Andres J Garcia and Yasuhiro Horiike

2011-01-01

228

The Role of the Self in Responses to Health Communications: A Cultural Perspective  

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To the extent that cultures vary in how they shape individuals’ self-construal, it is important to consider a cultural perspective to understand the role of the self in health persuasion. We review recent research that has adopted a cultural perspective on how to frame health communications to be congruent with important, culturally variant, aspects of the self. Matching features of a health message to approach vs. avoidance orientation and independent vs. interdependent self-construal can ...

Sherman, David K.; Uskul, Ayse K.; Updegraff, John A.

2011-01-01

229

Heterogeneous response to X-ray and ultraviolet light irradiations of cultured skin fibroblasts in two families with Gardner's Syndrome  

International Nuclear Information System (INIS)

A heterogeneous response to X-ray and far UV (254 nm) light irradiations was found in cultured skin fibroblast lines from 2 separate families with Gardner's syndrome. When compared to 2 normal control cultures and cultures from 2 patients with nonfamilial colon cancer, cultures from 4 clinically affected members of family 1 showed increased sensitivity to the lethal effects of both X-ray and UV light irradiations. These cells also showed a delayed pattern of X-ray potentially lethal damage repair (PLDR) and absent UV PLDR. In contrast, cultures from 3 members of family 2 (2 of whom were clinically affected) showed a normal response of survival and PLDR to both X-ray and UV light irradiations. Thus increased sensitivity of cultured skin fibroblasts to X-ray and UV light irradiations was not a consistent in vitro finding in patients with Gardner's syndrome. However, in families with Gardner's syndrome who demonstrate in vitro radiosensitivity, additional studies are needed to assess the usefulness of these techniques in detecting affected individuals prior to the development of colon carcinoma and other manifestations

1982-01-01

230

The effects of intestinal LPS exposure on inflammatory responses in a porcine enterohepatic co-culture system.  

Science.gov (United States)

A porcine enterohepatic co-culture system, with primary hepatocytes as bottom layer and IPEC-J2 epithelial cells as upper layer, was developed to study the effects of lipopolysaccharides (LPS) on the gene expression profile of pro-inflammatory cytokines (interleukin-8 (IL-8) and tumor necrosis factor-?) and CYP enzymes (CYP1A1, CYP1A2, CYP3A29). The barrier integrity of IPEC-J2 cells was investigated by transepithelial electrical resistance measurements and by fluorescein isothiocyanate-dextran-based test. Basolateral IL-8 production was significantly elevated in LPS-treated IPEC-J2 and primary hepatocyte mono-cultures as well as in the co-culture system, in a dose-independent manner. The LPS-induced changes in the expression of the CYP1A2 and CYP3A29 genes in hepatocyte mono-cultures differed from those in co-culture after LPS treatment on the apical side of the IPEC-J2 cell layer. CYP1A2 was downregulated by the LPS treatment in mono-cultures but upregulated at 10 ?g/ml LPS in co-culture; gene expression of CYP3A29 showed no significant LPS-induced change in the hepatocyte mono-culture but was significantly downregulated in co-culture. The newly established co-culture system capable of mimicking enterohepatic interplay in LPS-induced inflammatory responses in vitro can be used in the future for reliable screening of potential anti-inflammatory compounds. PMID:24049015

Paszti-Gere, Erzsebet; Matis, Gabor; Farkas, Orsolya; Kulcsar, Anna; Palocz, Orsolya; Csiko, Gyorgy; Neogrady, Zsuzsanna; Galfi, Peter

2014-02-01

231

Corporate Social Responsibility : WalMart, Maersk and the Cultural Bounds of Representation in Corporate Web Sites  

DEFF Research Database (Denmark)

Understanding Corporate Social Responsibility (CSR) as having explicit policies and implicit norms situated in cultural systems highlights the connections between institutional and cultural structures of nation states and business' commitment to CSR as reflected in the strategies used to communicate CSR to public audiences via the Internet.  To frame CSR from a situated perspective (Matten & Moon 2005) implies a shift in understanding relations between corporations and their stakeholders from a corporate-centered model to a cultural systems perspective.  This paper describes an approach to cultural systems in which can be used to frame our understanding of implicit norms with respect to CSR, and demonstrates how these norms result in different practices of communicating CSR in the WalMart and Maersk corporate websites.

Kampf, Constance

2007-01-01

232

Phylogenetic evidence of host-specific cryptic species in the anther smut fungus.  

Science.gov (United States)

Cryptic structure of species complexes confounds an accurate accounting of biological diversity in natural systems. Also, cryptic sibling species often become specialized to different ecological conditions, for instance, with host specialization by cryptic parasite species. The fungus Microbotryum violaceum causes anther smut disease in plants of Caryophyllaceae, and the degree of specialization and gene flow between strains on different hosts have been controversial in the literature. We conducted molecular phylogenetic analyses on M. violaceum from 23 host species and different geographic origins using three single-copy nuclear genes (beta-tub, gamma-tub, and Ef1alpha). Congruence between the phylogenies identified several lineages that evolved independently for a long time. The lineages had overlapping geographic ranges but were highly specialized on different hosts. These results thus suggest that M. violaceum is a complex of highly specialized sibling species. Two incongruencies between the individual gene phylogenies and one intragene recombination event were detected at basal nodes, suggesting ancient introgression events or speciation events via hybridizations. However, incongruencies and recombination were not detected among terminal branches, indicating that the potentials for cross-infection and experimental hybridization are often not sufficient to suggest that introgressions would likely persist in nature. PMID:17300424

Le Gac, Mickael; Hood, Michael E; Fournier, Elisabeth; Giraud, Tatiana

2007-01-01

233

Extensive divergence between mating-type chromosomes of the anther-smut fungus.  

Science.gov (United States)

Genomic regions that determine mating compatibility are subject to distinct evolutionary forces that can lead to a cessation of meiotic recombination and the accumulation of structural changes between members of the homologous chromosome pair. The relatively recent discovery of dimorphic mating-type chromosomes in fungi can aid the understanding of sex chromosome evolution that is common to dioecious plants and animals. For the anther-smut fungus, Microbotryum lychnidis-dioicae (= M. violaceum isolated from Silene latifolia), the extent of recombination cessation on the dimorphic mating-type chromosomes has been conflictingly reported. Comparison of restriction digest optical maps for the two mating-type chromosomes shows that divergence extends over 90% of the chromosome lengths, flanked at either end by two pseudoautosomal regions. Evidence to support the expansion of recombination cessation in stages from the mating-type locus toward the pseudoautosomal regions was not found, but evidence of such expansion could be obscured by ongoing processes that affect genome structure. This study encourages the comparison of forces that may drive large-scale recombination suppression in fungi and other eukaryotes characterized by dimorphic chromosome pairs associated with sexual life cycles. PMID:23150606

Hood, Michael E; Petit, Elsa; Giraud, Tatiana

2013-01-01

234

From Inaction to External Whistleblowing: The Influence of the Ethical Culture of Organizations on Employee Responses to Observed Wrongdoing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Putting measures in place to prevent wrongdoing in organizations is important, but detecting and correcting wrongdoing is just as vital. Employees who observe wrongdoing should therefore be encouraged to respond in a manner that supports corrective action. This paper examines the influence of the ethical culture of organizations on employee responses to observed wrongdoing.

Kaptein, S. P.

2009-01-01

235

Assessing Autistic Traits in a Taiwan Preschool Population: Cross-Cultural Validation of the Social Responsiveness Scale (SRS)  

Science.gov (United States)

The cross-cultural validity of the Mandarin-adaptation of the social responsiveness scale (SRS) was examined in a sample of N = 307 participants in Taiwan, 140 typically developing and 167 with clinically-diagnosed developmental disorders. This scale is an autism assessment tool that provides a quantitative rather than categorical measure of…

Wang, Jessica; Lee, Li-Ching; Chen, Ying-Sheue; Hsu, Ju-Wei

2012-01-01

236

Effects of Science Interest and Environmental Responsibility on Science Aspiration and Achievement: Gender Differences and Cultural Supports  

Science.gov (United States)

The aim of the present study is twofold: (1) to investigate gender differences in the effects of science interest and environmental responsibility on science aspiration and achievement and (2) to explore the relations between cultural supports (macroeconomic and gender equality) and both boys' and girls' tendencies to integrate the aforementioned…

Chiu, Mei-Shiu

2010-01-01

237

Growth response and survival of Heterobranchus longifilis cultured at different water levels in outdoor concrete tanks  

Directory of Open Access Journals (Sweden)

Full Text Available Thirteen-day-old hatchery-raised fry obtained from hormonally-induced spawns of mature African catfish H. longifilis brood stock were introduced to three different water levels (0.35, 0.50 and 0.65m in four replicates in 12 units of 2x2x1m3 outdoor concrete tanks. The fry were similarly stocked initially at 50 fry m-2 and later thinned down to 5 fish m-2 and cultured for 6 months. Fish were fed twice daily with commercial pellet feeds (Coppens™ while adjusting the feeding rate from 10 to 4% body weight and pellet size from 0.2 to 4.5 mm. The effects of pond water levels were evaluated in growth responses and survival. Water quality variables were similar (p > 0.05 in all compartments. Temperature, dissolved oxygen and pH were at the optimum level for fish. The results reveal significant (P H. longifilis from fry to sub-adult and from the grow-out/fattening of sub-adult to adult, respectively, in outdoor concrete tanks.

Anthony A. Nlewadim

2011-07-01

238

Characterization and response of newly developed high-grade glioma cultures to the tyrosine kinase inhibitors, erlotinib, gefitinib and imatinib.  

LENUS (Irish Health Repository)

High-grade gliomas (HGG), are the most common aggressive brain tumours in adults. Inhibitors targeting growth factor signalling pathways in glioma have shown a low clinical response rate. To accurately evaluate response to targeted therapies further in vitro studies are necessary. Growth factor pathway expression using epidermal growth factor receptor (EGFR), mutant EGFR (EGFRvIII), platelet derived growth factor receptor (PDGFR), C-Kit and C-Abl together with phosphatase and tensin homolog (PTEN) expression and downstream activation of AKT and phosphorylated ribosomal protein S6 (P70S6K) was analysed in 26 primary glioma cultures treated with the tyrosine kinase inhibitors (TKIs) erlotinib, gefitinib and imatinib. Response to TKIs was assessed using 50% inhibitory concentrations (IC(50)). Response for each culture was compared with the EGFR\\/PDGFR immunocytochemical pathway profile using hierarchical cluster analysis (HCA) and principal component analysis (PCA). Erlotinib response was not strongly associated with high expression of the growth factor pathway components. PTEN expression did not correlate with response to any of the three TKIs. Increased EGFR expression was associated with gefitinib response; increased PDGFR-? expression was associated with imatinib response. The results of this in vitro study suggest gefitinib and imatinib may have therapeutic potential in HGG tumours with a corresponding growth factor receptor expression profile.

Kinsella, Paula

2012-03-10

239

Regeneração in vitro de anteras de arroz irrigado (Oryza sativa L.) e mapeamento de QTL associado / In vitro regeneration of irrigated rice (Oryza sativa L.) anthers and detection of associated QTL  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A baixa taxa de regeneração in vitro de alguns cultivares de arroz da subespécie indica limita a utilização de técnicas de cultura de anteras como ferramenta para o desenvolvimento de novos cultivares. A identificação de regiões genômicas associadas à formação de calos e regeneração de plantas, a pa [...] rtir do cultivo de anteras, poderá permitir a transferência do caráter por seleção assistida. Duas populações de retrocruzamento foram utilizadas para o mapeamento genético e estudo destes caracteres, sendo Taipei 309// BRS 7 "Taim"/Taipei 309 (53 genótipos) e BRS 7 "Taim"// BRS 7 "Taim"/Taipei 309 (74 genótipos). Duzentas anteras imaturas de cada genótipo utilizado no estudo foram inoculadas em meio NL líquido e, após 40 dias, os calos formados foram transferidos para o meio MS sólido para regeneração de plantas. Todas as plantas doadoras de anteras foram usadas na extração de DNA genômico e sete primers RAPD foram utilizados na geração de marcadores para a construção dos mapas de ligação dos retrocruzamentos estudados. A taxa de formação de calos variou de 2,27 a 3,36% e a taxa de regeneração de plantas 1,38 a 1,82%, não se diferenciando significativamente. Seis grupos de ligação foram obtidos, três em cada população. Um QTL com LOD 3,10 foi detectado para o caráter formação de calos na população Taipei 309 // BRS 7 "Taim" / Taipei 309. Nenhum QTL foi detectado para a característica regeneração de plantas. Abstract in english The low in vitro regeneration of some indica rice cultivars, limits the use of anther culture techniques as a tool to reduce the time for releasing new cultivars. The identification of genomic regions associated with callus formation and in vitro regeneration from anther culture, will facilitate sel [...] ection of these traits through marker assisted techniques. Two backcross populations were used to study and map these traits, Taipei 309// BRS 7 "Taim"/Taipei 309 (53 genotypes) and BRS 7 "Taim"// BRS 7 "Taim"/Taipei 309 (74 genotypes). Two hundred immature anthers, from each genotype used in this study, were inoculated in liquid NL medium for callus induction and, after 40 days, the formed callus were transferred to solid MS medium for plant regeneration. Each anther donor plant was used for DNA extraction and seven RAPD primers were used to assess genomic regions associated to callus formation and plant regeneration. As results, callus formation ranged from 2.27 up to 3.36% and plant regeneration ranged from 1.38 up to 1.82%, no significant differences were observed. Six linkage groups were obtained, being three from each population. One QTL was detected associated to callus formation, with LOD score 3.10, in the population Taipei 309 // BRS 7 "Taim" / Taipei 309. No QTL association was detected to the trait plant regeneration.

Sérgio Dias, Lannes; Paulo Dejalma, Zimmer; Antonio Costa de, Oliveira; Fernando Irajá Félix de, Carvalho; Eduardo Alano, Vieira; Ariano Martins de, Magalhães Junior; Maurício Marini, Kopp; Fábio Almeida de, Freitas.

240

Initiation of an Inflammatory Response in Resident Intestinal Lamina Propria Cells -Use of a Human Organ Culture Model  

Science.gov (United States)

Resident human lamina propria immune cells serve as powerful effectors in host defense. Molecular events associated with the initiation of an intestinal inflammatory response in these cells are largely unknown. Here, we aimed to characterize phenotypic and functional changes induced in these cells at the onset of intestinal inflammation using a human intestinal organ culture model. In this model, healthy human colonic mucosa was depleted of epithelial cells by EDTA treatment. Following loss of the epithelial layer, expression of the inflammatory mediators IL1B, IL6, IL8, IL23A, TNFA, CXCL2, and the surface receptors CD14, TLR2, CD86, CD54 was rapidly induced in resident lamina propria cells in situ as determined by qRT-PCR and immunohistology. Gene microarray analysis of lamina propria cells obtained by laser-capture microdissection provided an overview of global changes in gene expression occurring during the initiation of an intestinal inflammatory response in these cells. Bioinformatic analysis gave insight into signalling pathways mediating this inflammatory response. Furthermore, comparison with published microarray datasets of inflamed mucosa in vivo (ulcerative colitis) revealed a significant overlap of differentially regulated genes underlining the in vivo relevance of the organ culture model. Furthermore, genes never been previously associated with intestinal inflammation were identified using this model. The organ culture model characterized may be useful to study molecular mechanisms underlying the initiation of an intestinal inflammatory response in normal mucosa as well as potential alterations of this response in inflammatory bowel disease.

Schroder-Braunstein, Jutta; Gras, Judith; Brors, Benedikt; Schwarz, Sonja; Szikszai, Timea; Lasitschka, Felix; Wabnitz, Guido; Heidtmann, Antje; Lee, Young-Seon; Schiessling, Serin; Leowardi, Christine; Al-Saeedi, Mohammed; Ulrich, Alexis; Engelke, Antonia; Winter, Johannes; Samstag, Yvonne; Giese, Thomas; Meuer, Stefan

2014-01-01

 
 
 
 
241

How cultural capital, habitus and class influence the responses of older adults to the field of contemporary visual art?  

Science.gov (United States)

This article explores the responses of 38 older people to contemporary visual art through the results of a 28-month study entitled, Contemporary Visual Art and Identity Construction: Wellbeing amongst Older People. A framework for the analysis is provided by previous work on the consumption of art and by Bourdieu's constructs of cultural capital, habitus and field. Five groups of older people, with a range of different backgrounds, were taken to galleries and their responses were recorded, transcribed and analysed. It is concluded that participants’ responses are influenced by their cultural capital, habitus and class—which, in turn, are affected by their life course experiences. Those who could not recognise the field (e.g., did not view contemporary art as “art”) created their own meanings that they associated with the artworks. Evidence indicates that group dynamics and class mobility are likewise important. Participants also used the experience to respond to real or anticipated age-associated deficits.

Newman, Andrew; Goulding, Anna; Whitehead, Christopher

2013-01-01

242

The Role of the Self in Responses to Health Communications: A Cultural Perspective.  

Science.gov (United States)

To the extent that cultures vary in how they shape individuals' self-construal, it is important to consider a cultural perspective to understand the role of the self in health persuasion. We review recent research that has adopted a cultural perspective on how to frame health communications to be congruent with important, culturally variant, aspects of the self. Matching features of a health message to approach vs. avoidance orientation and independent vs. interdependent self-construal can lead to greater message acceptance and health behavior change. Discussion centers on the theoretical and applied value of the self as an organizing framework for constructing persuasive health communications. PMID:21980260

Sherman, David K; Uskul, Ayse K; Updegraff, John A

2011-07-01

243

Physiological Responses of Rice Seedling (Oryza sativa L. to Salt-stress Cultured under in vitro Photomixotrophic and Photoautotrophic Systems  

Directory of Open Access Journals (Sweden)

Full Text Available Physiological responses of crop species to salt-stress in conventional in vitro culture may be found some errors due to sucrose as a main carbon source, causing to erratic data. Seven-day-old in vitro seedlings were aseptically transferred to culture under photoautotrophic and photomixotrophic systems for 13 days, subsequently adjusted to 0 and 342 mM NaCl. The pigment degradation of seedlings grown in 342 mM NaCl was positively related to NPR reduction in both the photoautotrophic (r=0.84 and the photomixotrophic system (r=0.95. This resulted in low growth, as measured by leaf expansion, shoot height, root length, fresh weight and dry weight. Moreover, the NPR reduction of seedlings cultured with 342 mM NaCl was positively related to the low survival percentage for both the photoautotrophic (r=0.96 and the photomixotrophic system (r=0.98. Moreover, the phenotypic responses of photoautotrophic seedlings to salt-stress expressed a more realistic phenotype than the photomixotrophic system. Besides, the phenotypic expression of seedlings cultured under photoautotrophic system responded more sensitively to salt-stress than those photomixotrophic system. Therefore, study of the phenotypic responses of seedlings to salt-stress would make use of the photoautotrophic system. This system should be a novel process for phenotypic expression of in vitro to salt stress.

Suriyan Cha-um

2005-01-01

244

A refined in vitro model to study inflammatory responses in organotypic membrane culture of postnatal rat hippocampal slices  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Propagated tissue degeneration, especially during aging, has been shown to be enhanced through potentiation of innate immune responses. Neurodegenerative diseases and a wide variety of inflammatory conditions are linked together and several anti-inflammatory compounds considered as having therapeutic potential for example in Alzheimer's disease (AD. In vitro brain slice techniques have been widely used to unravel the complexity of neuroinflammation, but rarely, has the power of the model itself been reported. Our aim was to gain a more detailed insight and understanding of the behaviour of hippocampus tissue slices in serum-free, interface culture per se and after exposure to different pro- and anti-inflammatory compounds. Methods The responses of the slices to pro- and anti-inflammatory stimuli were monitored at various time points by measuring the leakage of lactate dehydrogenase (LDH and the release of cytokines interleukin 6 (IL-6 and tumour necrosis factor alpha (TNF-? and nitric oxide (NO from the culture media. Histological methods were applied to reveal the morphological status after exposure to stimuli and during the time course of the culture period. Statistical power analysis were made with nQuery Advisor®, version 5.0, (Statistical Solutions, Saugus, MA computer program for Wilcoxon (Mann-Whitney rank-sum test. Results By using the interface membrane culture technique, the hippocampal slices largely recover from the trauma caused by cutting after 4–5 days in vitro. Furthermore, the cultures remain stable and retain their responsiveness to inflammatory stimuli for at least 3 weeks. During this time period, cultures are susceptible to modification by inflammatory stimuli as assessed by quantitative biochemical assays and morphological characterizations. Conclusion The present report outlines the techniques for studying immune responses using a serum-free slice culture model. Statistically powerful data under controlled culture conditions and with ethically justified use of animals can be obtained as soon as after 4–5 DIV. The model is most probably suitable also for studies of chronic inflammation.

Miettinen Riitta

2005-11-01

245

Difference in Osteoclast Responses to Tricalcium Phosphate in Culture Medium Supplemented with Zinc and to Zinc-Containing Tricalcium Phosphate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Difference in osteoclast responses (i.e., apoptosis, actin ring formation) to tricalcium phosphate (TCP) in culture medium supplemented with zinc and to zinc-containing tricalcium phosphate (ZnTCP) was investigated in this study. On the TCP ceramic, an increase in zinc ion in the culture medium within the range between 0.3 and 6.8 ppm significantly induced an increase in osteoclast apoptosis and a decrease in actin ring formation. However, even a high level of magnesium ion up to 100 ppm in t...

Xia Li; Koji Senda; Atsuo Ito; Yu Sogo; Atsushi Yamazaki

2011-01-01

246

C. P. Snow's "The Two Cultures": Michael Polanyi's Response and Context  

Science.gov (United States)

C. P. Snow's "The Two Cultures" controversially contrasted science and literature, suggesting that neither scientists nor literary intellectuals have much in common with, and seldom bother speaking to, the other. Responding to Snow, Michael Polanyi argued that specialization has made modern culture, not twofold but manifold. In his major work,…

Jacobs, Struan

2011-01-01

247

Lyric Reader: Creating Intrinsically Motivating and Culturally Responsive Reading Environments. CIERA Report.  

Science.gov (United States)

This report addresses the question of whether culturally specific strategies are an effective means for literacy instruction, and how a culturally specific computer-based architecture, the "Lyric Reader," takes advantage of children's existing knowledge and experience to motivate them to read. Given the reading difficulties experienced by many…

Pinkard, Nichole

248

A sensitive sensor cell line for the detection of oxidative stress responses in cultured human keratinocytes.  

Science.gov (United States)

In the progress of allergic and irritant contact dermatitis, chemicals that cause the generation of reactive oxygen species trigger a heat shock response in keratinocytes. In this study, an optical sensor cell line based on cultured human keratinocytes (HaCaT cells) expressing green fluorescent protein (GFP) under the control of the stress-inducible HSP70B' promoter were constructed. Exposure of HaCaT sensor cells to 25 µM cadmium, a model substance for oxidative stress induction, provoked a 1.7-fold increase in total glutathione and a ~300-fold induction of transcript level of the gene coding for heat shock protein HSP70B'. An extract of Arnica montana flowers resulted in a strong induction of the HSP70B' gene and a pronounced decrease of total glutathione in keratinocytes. The HSP70B' promoter-based sensor cells conveniently detected cadmium-induced stress using GFP fluorescence as read-out with a limit of detection of 6 µM cadmium. In addition the sensor cells responded to exposure of cells to A. montana extract with induction of GFP fluorescence. Thus, the HaCaT sensor cells provide a means for the automated detection of the compromised redox status of keratinocytes as an early indicator of the development of human skin disorders and could be applied for the prediction of skin irritation in more complex in vitro 3D human skin models and in the development of micro-total analysis systems (µTAS) that may be utilized in dermatology, toxicology, pharmacology and drug screenings. PMID:24967604

Hofmann, Ute; Priem, Melanie; Bartzsch, Christine; Winckler, Thomas; Feller, Karl-Heinz

2014-01-01

249

A Sensitive Sensor Cell Line for the Detection of Oxidative Stress Responses in Cultured Human Keratinocytes  

Directory of Open Access Journals (Sweden)

Full Text Available In the progress of allergic and irritant contact dermatitis, chemicals that cause the generation of reactive oxygen species trigger a heat shock response in keratinocytes. In this study, an optical sensor cell line based on cultured human keratinocytes (HaCaT cells expressing green fluorescent protein (GFP under the control of the stress-inducible HSP70B’ promoter were constructed. Exposure of HaCaT sensor cells to 25 µM cadmium, a model substance for oxidative stress induction, provoked a 1.7-fold increase in total glutathione and a ~300-fold induction of transcript level of the gene coding for heat shock protein HSP70B’. An extract of Arnica montana flowers resulted in a strong induction of the HSP70B’ gene and a pronounced decrease of total glutathione in keratinocytes. The HSP70B’ promoter-based sensor cells conveniently detected cadmium-induced stress using GFP fluorescence as read-out with a limit of detection of 6 µM cadmium. In addition the sensor cells responded to exposure of cells to A. montana extract with induction of GFP fluorescence. Thus, the HaCaT sensor cells provide a means for the automated detection of the compromised redox status of keratinocytes as an early indicator of the development of human skin disorders and could be applied for the prediction of skin irritation in more complex in vitro 3D human skin models and in the development of micro-total analysis systems (µTAS that may be utilized in dermatology, toxicology, pharmacology and drug screenings.

Ute Hofmann

2014-06-01

250

Multiple infections by the anther smut pathogen are frequent and involve related strains.  

Science.gov (United States)

Population models of host-parasite interactions predict that when different parasite genotypes compete within a host for limited resources, those that exploit the host faster will be selected, leading to an increase in parasite virulence. When parasites sharing a host are related, however, kin selection should lead to more cooperative host exploitation that may involve slower rates of parasite reproduction. Despite their potential importance, studies that assess the prevalence of multiple genotype infections in natural populations remain rare, and studies quantifying the relatedness of parasites occurring together as natural multiple infections are particularly scarce. We investigated multiple infections in natural populations of the systemic fungal plant parasite Microbotryum violaceum, the anther smut of Caryophyllaceae, on its host, Silene latifolia. We found that multiple infections can be extremely frequent, with different fungal genotypes found in different stems of single plants. Multiple infections involved parasite genotypes more closely related than would be expected based upon their genetic diversity or due to spatial substructuring within the parasite populations. Together with previous sequential inoculation experiments, our results suggest that M. violaceum actively excludes divergent competitors while tolerating closely related genotypes. Such an exclusion mechanism might explain why multiple infections were less frequent in populations with the highest genetic diversity, which is at odds with intuitive expectations. Thus, these results demonstrate that genetic diversity can influence the prevalence of multiple infections in nature, which will have important consequences for their optimal levels of virulence. Measuring the occurrence of multiple infections and the relatedness among parasites within hosts in natural populations may be important for understanding the evolutionary dynamics of disease, the consequences of vaccine use, and forces driving the population genetic structure of parasites. PMID:18020704

López-Villavicencio, Manuela; Jonot, Odile; Coantic, Amélie; Hood, Michael E; Enjalbert, Jérôme; Giraud, Tatiana

2007-11-01

251

Cultivate in vitro of wheat Anthers (Triticum Aestivum L.) In the ICA-TENZA and PAV -76 varieties  

International Nuclear Information System (INIS)

The objective of the present work consisted, in determining the cultivation conditions under which it was possible to induce through the technique of the cultivation of anthers, the callus formation and possible regeneration of green plants of wheat (Triticum aestivum L.) in the varieties ICA-Tenza and Pav -76. With the purpose of identifying the but appropriate state of development of the grain of pollen for the inoculation of the anthers, a cytologic study was made in which was correlation among the moriolic parameters of the plant; (inter liguler distances, auricle-knot distances and longitude of the edges) and the state of development of the microspore; Of the parameters, it was recommended to keep in mind the longitude from the edges when harvesting the experimental material. The anthers of both genotypes were inoculated in the means bases Pope 4 and N6, with hormonal levels of ELL (naftalen acetic acid) of 0.0, 0.5 and 1.0 mg/I. the answers of the genotypes were evaluated before the means of basal cultivation, in connection with the induction of tripes and the plants regeneration. Of the two used genotypes, the Pav -76 it presented bigger capacity to induce the formation of tripes, while the ICA-Tenza genotype presented a bigger answer capacity in the regeneration of plants so much green as albino. The results obtained allowed to establish that a relationship exists between the means of cultivation and the capacity of the genotypes to regenerate as much tripes as plants. Due to the drop survival of the regenerated plants, it was not possible to settle down with clarity a relationship of the ploidia level

1994-01-01

252

Activation of antioxidant response element in mouse primary cortical cultures with sesquiterpene lactones isolated from Tanacetum parthenium  

Science.gov (United States)

Tanacetum parthenium (Asteraceae) produces biologically active sesquiterpene lactones (SL). Nuclear factor E2-related factor 2 (Nrf2) is a transcription factor known to activate a series of genes termed the antioxidant response element (ARE). Activation of the Nrf2/ARE may be useful for the treatment of neurodegenerative disease. In this study we isolated 11 sesquiterpene lactones from T. parthenium with centrifugal partition chromatography and semi-preparative HPLC. Compounds were screened in-vitro for their ability to activate the ARE on primary mouse cortical cultures as well as for their toxicity towards the cultures. All sesquiterpene lactones containing the ?-methylene-?-lactone moiety were able to activate the ARE although a number of compounds displayed significant cellular toxicity towards the cultures. The structure activity relationship of the sesquiterpene lactones indicate that the guaianolides isolated were more active and less toxic then the germacranolides.

Fischedick, Justin T; Standiford, Miranda; Johnson, Delinda A.; De Vos, Ric C.H.; Todorovic, Sla?ana; Banjanac, Tijana; Verpoorte, Rob; Johnson, Jeffrey A.

2012-01-01

253

Expression of Heat Shock and Other Stress Response Proteins in Ticks and Cultured Tick Cells in Response to Anaplasma spp. Infection and Heat Shock  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ticks are ectoparasites of animals and humans that serve as vectors of Anaplasma and other pathogens that affect humans and animals worldwide. Ticks and the pathogens that they transmit have coevolved molecular interactions involving genetic traits of both the tick and the pathogen that mediate their development and survival. In this paper, the expression of heat shock proteins (HSPs) and other stress response proteins (SRPs) was characterized in ticks and cultured tick cells by proteomics an...

Villar, Margarita; Ayllo?n, Nieves; Busby, Ann T.; Galindo, Ruth C.; Blouin, Edmour F.; Kocan, Katherine M.; Bonzo?n-kulichenko, Elena; Zivkovic, Zorica; Almaza?n, Consuelo; Torina, Alessandra; Va?zquez, Jesu?s; La Fuente, Jose?

2010-01-01

254

Randomised Response Technique-An Innovative Method To Measure Culturally Sensitive Variables : Results From A Pilot Study  

Directory of Open Access Journals (Sweden)

Full Text Available Research questions: What is the advantage of Randomized Response Technique (RRT over the conventional Direct Interview (DI and Anonymous Questionnaire (AQ in the assessment of culturally sensitive variables? Objectives: To compare the efficacy of the three methods, namely RRT, DI and AQ in the measurement of prevalence of Pre/Extra marital sex. Study design: Cross sectional study, using the three methods. Setting: A pilot study in a given community in Pondicherry. Statistical analysis: Probability equations. Results: The prevalence of pre/extra marital sex in the study population by the DI, AQ and RRT methods were 0%, 6% and 10% respectively in this pilot study. Conclusion: RRT improves validity of measurement of culturally sensitive variables both by ensuring a high participation in the study and by enabling a true response by assuring full confidentiality of information.

Soudarssanane M. B

2003-01-01

255

Conserved host response to highly pathogenic avian influenza virus infection in human cell culture, mouse and macaque model systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Understanding host response to influenza virus infection will facilitate development of better diagnoses and therapeutic interventions. Several different experimental models have been used as a proxy for human infection, including cell cultures derived from human cells, mice, and non-human primates. Each of these systems has been studied extensively in isolation, but little effort has been directed toward systematically characterizing the conservation of h...

McDermott Jason E; Shankaran Harish; Eisfeld Amie J; Belisle Sarah E; Neuman Gabriele; Li Chengjun; McWeeney Shannon; Sabourin Carol; Kawaoka Yoshihiro; Katze Michael G; Waters Katrina M

2011-01-01

256

Randomised Response Technique-An Innovative Method To Measure Culturally Sensitive Variables : Results From A Pilot Study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Research questions: What is the advantage of Randomized Response Technique (RRT) over the conventional Direct Interview (DI) and Anonymous Questionnaire (AQ) in the assessment of culturally sensitive variables? Objectives: To compare the efficacy of the three methods, namely RRT, DI and AQ in the measurement of prevalence of Pre/Extra marital sex. Study design: Cross sectional study, using the three methods. Setting: A pilot study in a given community in Pondicherry. Statistical analysis: Pro...

Soudarssanane M. B; Naik Balaji; Sahai Ajit; Bazroy Joy

2003-01-01

257

Greening of organizational culture : Factors influencing the individual's environmental responsibility in a multinational organization – The case of KONE Corporation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Objective of the thesis This is an interdisciplinary study that combines theoretical elements from the field on sustainable management, social and organizational psychology, management and international business. Its aim is to carefully assess environmental organizational cultural change and, in particular, by looking at factors that influence an individual in an organization to act in a more environmentally responsible way. Therefore, the aim of this study is to identify such influential ...

Nurkka, Johanna

2009-01-01

258

Deficient repair response of IPF fibroblasts in a co-culture model of epithelial injury and repair  

Science.gov (United States)

Background Idiopathic pulmonary fibrosis (IPF) is a progressive disorder marked by relentless fibrosis and damage of the lung architecture. A growing body of evidence now suggests that IPF progresses as a result of aberrant epithelial-fibroblast crosstalk. Injured epithelia are a major source of growth factors such as PDGF which guide resident fibroblasts to injury sites. Results In this study, we utilized a novel co-culture system to investigate the effect of fibroblast phenotype on their response to epithelial injury. Fibroblasts from normal lungs (NHLF) responded to epithelial injury and populated the wound site forming a fibroblast plug/mechanical barrier which prevented epithelial wound closure. IPF fibroblasts were impaired in their response to epithelial injury. They also expressed reduced PDGFR? compared to NHLFs and were defective towards PDGF-AA mediated directional movement. Neutralization of PDGF-AA and pan-PDGF but not PDGF-BB reduced the injury response of NHLFs thereby preventing the formation of the mechanical barrier and promoting epithelial wound closure. Co-culture of epithelial cells with IPF fibroblasts led to marked increase in the levels of pro-fibrotic growth factors - bFGF and PDGF and significant depletion of anti-fibrotic HGF in the culture medium. Furthermore, IPF fibroblasts but not NHLFs induced a transient increase in mesenchymal marker expression in the wound lining epithelial cells. This was accompanied by increased migration and faster wound closure in co-cultures with IPF fibroblasts. Conclusions Our data demonstrate that the IPF fibroblasts have an aberrant repair response to epithelial injury.

2014-01-01

259

Quantitative morphodynamics of endothelial cells within confluent cultures in response to fluid shear stress.  

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To evaluate shear stress-induced effects on cultured cells we have extended the mechanical setup of a multichannel in vitro rheological system and developed software allowing entire processing control and image data analysis. The values of cell motility, degree of orientation (alignment), and cell elongation were correlated as a function of time (morphodynamics). Collective and individual endothelial cells within confluent cultures displayed a shear stress-dependent characteristic phase behav...

2000-01-01

260

Effects of Culture and Education on Ethical Responses on Our Global Society  

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Two trends that affect communications are prevalent today: a focus on ethics in the U.S. business operations and an increasingly global society and marketplace. This research project brings together these trends to gain a more in-depth understanding of the impact of culture on ethical education. By surveying students in six countries around the globe, this study was able to get at the divergent cultural frameworks utilized in ethical decision making. The results offer a significant contributi...

2012-01-01

 
 
 
 
261

Alteration of cellular behavior and response to PI3K pathway inhibition by culture in 3D collagen gels.  

Science.gov (United States)

Most investigations into cancer cell drug response are performed with cells cultured on flat (2D) tissue culture plastic. Emerging research has shown that the presence of a three-dimensional (3D) extracellular matrix (ECM) is critical for normal cell behavior including migration, adhesion, signaling, proliferation and apoptosis. In this study we investigate differences between cancer cell signaling in 2D culture and a 3D ECM, employing real-time, live cell tracking to directly observe U2OS human osteosarcoma and MCF7 human breast cancer cells embedded in type 1 collagen gels. The activation of the important PI3K signaling pathway under these different growth conditions is studied, and the response to inhibition of both PI3K and mTOR with PI103 investigated. Cells grown in 3D gels show reduced proliferation and migration as well as reduced PI3K pathway activation when compared to cells grown in 2D. Our results quantitatively demonstrate that a collagen ECM can protect U2OS cells from PI103. Overall, our data suggests that 3D gels may provide a better medium for investigation of anti-cancer drugs than 2D monolayers, therefore allowing better understanding of cellular response and behavior in native like environments. PMID:23110163

Fallica, Brian; Maffei, Joseph S; Villa, Shaun; Makin, Guy; Zaman, Muhammad

2012-01-01

262

The identification of QTLs associated with the in vitro response of rye (Secale cereale L.).  

Science.gov (United States)

This study was conducted in order to identify quantitative trait loci (QTLs) for the in vitro culture response of winter rye (Secale cereale L.) immature embryos and immature inflorescences. A genetic linkage map comprising 67 SSRs, 9 ISSRs, 13 SAMPLs, 7 RAPDs, 2 SCARs and one EST marker was created based on the analyses of 102 recombinant inbred lines from the cross between lines L318 (which has a good response in tissue cultures) and L9 (which is unable to regenerate plants from somatic tissues and anthers). The map spans 979.2 cM, and the average distance between markers is 9.9 cM. Two characteristics were evaluated: callus induction (CI) and somatic embryogenesis ability (SE). They were expressed as the percentage of immature embryos/inflorescences producing callus (designated ECI/ICI) and the percentage of explants producing somatic embryos (ESE/ISE). All the analysed traits showed continuous variation in the mapping population but a non-normal frequency distribution. We identified nine putative QTLs controlling the tissue culture response of rye, explaining up to 41.6% of the total phenotypic variation: two QTLs for ECI - eci-1, eci-2; 4 for ESE - ece-1, ese-2, ese-3, ese-4; 2 for ICI - ici-1, ici2; and 1 for ISE - ise-1. They were detected on chromosomes 1R, 4R, 5R, 6R and 7R. PMID:17579815

Bolibok, Hanna; Gruszczy?ska, Anna; Hromada-Judycka, Aneta; Rakoczy-Trojanowska, Monika

2007-01-01

263

Radiation-induced p53 protein response in the A549 cell line is culture growth-phase dependent  

International Nuclear Information System (INIS)

One role of the p53 tumor suppressor protein has been recently revealed. Kastan, M.B. reported that p53 protein accumulates in cells exposed to ionizing radiation. The accumulation of p53 protein is in response to DNA damage, most importantly double-strand breaks, that results from exposure to ionizing radiation. The rise in cellular p53 levels is necessary for an arrest in the G_1 phase of the cell cycle to provide additional time for DNA repair. The p53 response has also been demonstrated to enhance PCNA-dependent repair. p53 is thus an important regulator of the cellular response to DNA-damaging radiation. From this data, it can be concluded that the magnitude of the p53 response is not dependent on the phase of culture growth

1995-12-01

264

Radiation-induced p53 protein response in the A549 cell line is culture growth-phase dependent  

Energy Technology Data Exchange (ETDEWEB)

One role of the p53 tumor suppressor protein has been recently revealed. Kastan, M.B. reported that p53 protein accumulates in cells exposed to ionizing radiation. The accumulation of p53 protein is in response to DNA damage, most importantly double-strand breaks, that results from exposure to ionizing radiation. The rise in cellular p53 levels is necessary for an arrest in the G{sub 1} phase of the cell cycle to provide additional time for DNA repair. The p53 response has also been demonstrated to enhance PCNA-dependent repair. p53 is thus an important regulator of the cellular response to DNA-damaging radiation. From this data, it can be concluded that the magnitude of the p53 response is not dependent on the phase of culture growth.

Johnson, N.F.; Gurule, D.M.; Carpenter, T.R.

1995-12-01

265

Changes in cell biochemistry in response to culture of protoplasts with oxygenated perfluorocarbon.  

Science.gov (United States)

Superoxide dismutase (superoxide oxidoreductase; EC 1.15.1.1; SOD) was measured in enzymatically isolated protoplasts of Salpiglossis sinuata following culture in aqueous nutrient medium overlaying oxygen-gassed perfluorodecalin (Flutec PP6; BNFL Fluorochemicals, UK). SOD was extracted from harvested, lysed protoplast-derived cells after 1, 3, 7 and 14 days of culture and assayed spectrophotometrically. Protoplasts cultured with oxygenated PFC (+/- s.e.m, n = 5) showed significant increases in mean SOD activity to 4.2 +/- 0.1 U after 1 day (P < 0.05) and 9.3 +/- 0.7 U after 3 days (P < 0.01), with a fall in mean SOD after 7 days (5.1 +/- 0.9 U), similar to control. The decrease in SOD after 7 days correlated closely with a progressive fall in pO2 in the PFC phase over the same period. In contrast, control protoplasts (medium alone) or protoplasts cultured in medium overlaying non-oxygenated PFC showed no significant changes in mean SOD activity over the 14-day culture assessment period. PMID:9352063

Wardrop, J; Edwards, C M; Lowe, K C; Davey, M R; Power, J B

1997-11-01

266

No one likes a copycat: a cross-cultural investigation of children's response to plagiarism.  

Science.gov (United States)

Copying other people's ideas is evaluated negatively by American children and adults. The current study investigated the influence of culture on children's evaluations of plagiarism by comparing children from three countries--the United States, Mexico, and China--that differ in terms of their emphasis on the protection of intellectual property and ideas. Children (3- to 6-year-olds) were presented with videos involving two characters drawing pictures and were asked to evaluate the character who drew unique work or the character who copied someone else's drawing. The study showed that 5- and 6-year-olds from all three cultures evaluated copiers negatively compared with unique drawers. These results suggest that children from cultures that place different values on the protection of ideas nevertheless develop similar concerns with plagiarism by 5-year-olds. PMID:24473471

Yang, F; Shaw, A; Garduno, E; R Olson, K

2014-05-01

267

Concentration-dependent gene expression responses to flusilazole in embryonic stem cell differentiation cultures  

International Nuclear Information System (INIS)

The murine embryonic stem cell test (EST) is designed to evaluate developmental toxicity based on compound-induced inhibition of embryonic stem cell (ESC) differentiation into cardiomyocytes. The addition of transcriptomic evaluation within the EST may result in enhanced predictability and improved characterization of the applicability domain, therefore improving usage of the EST for regulatory testing strategies. Transcriptomic analyses assessing factors critical for risk assessment (i.e. dose) are needed to determine the value of transcriptomic evaluation in the EST. Here, using the developmentally toxic compound, flusilazole, we investigated the effect of compound concentration on gene expression regulation and toxicity prediction in ESC differentiation cultures. Cultures were exposed for 24 h to multiple concentrations of flusilazole (0.54-54 ?M) and RNA was isolated. In addition, we sampled control cultures 0, 24, and 48 h to evaluate the transcriptomic status of the cultures across differentiation. Transcriptomic profiling identified a higher sensitivity of development-related processes as compared to cell division-related processes in flusilazole-exposed differentiation cultures. Furthermore, the sterol synthesis-related mode of action of flusilazole toxicity was detected. Principal component analysis using gene sets related to normal ESC differentiation was used to describe the dynamics of ESC differentiation, defined as the 'differentiation track'. The concentration-dependent effects on development were reflected in the significance of deviation of flusilazole-exposed cultures from this transcriptomic-based differentiation track. Thus, the detection of developmental toxicity in EST using transcriptomics was shown to be compound concentration-dependent. This study provides further insight into the possible application of transcriptomics in the EST as an improved alternative model system for developmental toxicity testing.

2011-03-01

268

BYSTANDER RESPONSES IN THREE-DIMENSIONAL CULTURES CONTAINING RADIOLABELLED AND UNLABELLED HUMAN CELLS  

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Research on the radiation-induced bystander effect has been carried out mainly in 2-D tissue culture systems. This study uses a 3-D model, wherein apparently normal human diploid fibroblasts (AG1522) are grown in a carbon scaffold, to investigate the induction of a G1 checkpoint in bystander cells present alongside radiolabelled cells. Cultures were simultaneously pulse-labelled with 3H-deoxycytidine (3HdC) to selectively irradiate a minor fraction of cells, and bromodeoxyuridine (BrdU) to id...

Pinto, M.; Azzam, E. I.; Howell, R. W.

2006-01-01

269

Marker expression, behaviors, and responses vary in different lines of conditionally immortalized cultured podocytes  

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The state-of-the-art cultured podocyte is conditionally immortalized by expression of a temperature-sensitive mutant of the SV40 large-T antigen. These cultures proliferate at 33°C and differentiate at 37°C into arborized cells that more closely resemble in vivo podocytes. However, the degree of resemblance remains controversial. In this study, several parameters were measured in podocyte cell lines derived from mouse (JR, KE), human (MS), and rat (HK). In all lines, the quantities of NEPH1...

Chittiprol, Seetharamaiah; Chen, Phylip; Petrovic-djergovic, Danica; Eichler, Tad; Ransom, Richard F.

2011-01-01

270

In vivo-like drug responses of human tumors growing in three-dimensional gel-supported primary culture  

International Nuclear Information System (INIS)

An in vitro test of cell sensitivity to drugs that indicates in vivo response is an important need in cancer therapy and cancer drug development. Toward this end, the authors previously developed a collagen gel-supported culture system for growth of human tumors. This three-dimensional culture system is general and grows tumors at high frequency directly from surgery or biopsy that maintain important in vivo properties in vitro, including tissue architecture. They report here that with autoradiographic techniques measuring cellular DNA synthesis the drug responses of individual cells within the tissue structure of in vitro-grown tumors can be determined. Twenty tumor classes, including all the major ones, have been measured in toto at >50% frequency. Quantitative and qualitative results show increasing cell kill with rising cytotoxic drug concentration, differential drug sensitivities of multiple cell types within individual cultured tumors, differential sensitivities of a series of tumors of the same histopathological classification to a single drug, differential sensitivities of individual tumors to a series of drugs, and sensitivity patterns of various tumor types similar to the sensitivities found in vivo. Therefore, the results indicate that potentially important therapeutic data can be obtained from tumor specimens growing in vitro for the individual cancer patient as well as for rational and relevant screening for new agents active against human solid tumors

1987-01-01

271

In vivo-like drug responses of human tumors growing in three-dimensional gel-supported primary culture  

Energy Technology Data Exchange (ETDEWEB)

An in vitro test of cell sensitivity to drugs that indicates in vivo response is an important need in cancer therapy and cancer drug development. Toward this end, the authors previously developed a collagen gel-supported culture system for growth of human tumors. This three-dimensional culture system is general and grows tumors at high frequency directly from surgery or biopsy that maintain important in vivo properties in vitro, including tissue architecture. They report here that with autoradiographic techniques measuring cellular DNA synthesis the drug responses of individual cells within the tissue structure of in vitro-grown tumors can be determined. Twenty tumor classes, including all the major ones, have been measured in toto at >50% frequency. Quantitative and qualitative results show increasing cell kill with rising cytotoxic drug concentration, differential drug sensitivities of multiple cell types within individual cultured tumors, differential sensitivities of a series of tumors of the same histopathological classification to a single drug, differential sensitivities of individual tumors to a series of drugs, and sensitivity patterns of various tumor types similar to the sensitivities found in vivo. Therefore, the results indicate that potentially important therapeutic data can be obtained from tumor specimens growing in vitro for the individual cancer patient as well as for rational and relevant screening for new agents active against human solid tumors.

Vescio, R.A.; Redfern, C.H.; Nelson, T.J.; Ugoretz, S.; Stern, P.H.; Hoffman, R.M.

1987-07-01

272

Bystander responses in three-dimensional cultures containing radiolabelled and unlabelled human cells  

International Nuclear Information System (INIS)

Research on the radiation-induced bystander effect has been carried out mainly in 2-D tissue culture systems. This study uses a 3-D model, wherein apparently normal human diploid fibroblasts (AG1522) are grown in a carbon scaffold, to investigate the induction of a G1 checkpoint in bystander cells present alongside radiolabelled cells. Cultures were simultaneously pulse-labelled with 3H-deoxycytidine (3HdC) to selectively irradiate a minor fraction of cells, and bromodeoxyuridine (BrdU) to identify the radiolabelled cells. After thorough washing of cultures, iododeoxyuridine (IdU) was administered to detect proliferating bystander cells. The cultures were harvested at various times thereafter, and cells were reacted with two monoclonal antibodies specific to IdU/BrdU or BrdU, respectively, stained with propidium iodide, and subjected to multi-parameter flow cytometry. Cell-cycle progression was followed in radiolabelled cells (BrdU+) that were chronically irradiated by low energy beta particles emitted by DNA-incorporated 3H, and in unlabelled bystander cells (BrdU-) by a flow cytometry based cumulative labelling index assay. As expected, radiolabelled cells were delayed, in a dose-dependent manner, in G2 and subsequently G1. No delay occurred in progression of bystander cells through G1, when the labelled cells were irradiated at dose rates up to 0.32 Gy h-1. (authors)

2005-11-13

273

Overcoming Hindrances to Our Enduring Responsibility to the Ancestors: Protecting Traditional Cultural Places  

Science.gov (United States)

As first voiced by activists in the United States during the 1960s and 1970s and then sustained by other Native American leaders throughout the rest of the twentieth century, many Native American communities object to archaeological excavations and the wanton destruction of their traditional cultural places. In this article, the author discusses…

Martinez, Desiree Renee

2006-01-01

274

Culturally Responsive Pedagogy: Connecting New Zealand Teachers of Science with Their Maori Students  

Science.gov (United States)

This paper illustrates how important changes can occur in science learning and teaching if teachers take the trouble to understand and respect the cultural worlds of Indigenous students, and incorporate something of this understanding within their teaching practice. Ten teachers participated in a specially-designed one-year university postgraduate…

Glynn, Ted; Cowie, Bronwen; Otrel-Cass, Kathrin; Macfarlane, Angus

2010-01-01

275

Organisational Culture in Innovative Small to Medium Sized Enterprises (SMEs) : Leadership’s Responsibilities when Implementing Change as a Result of M&As  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study investigates what culturally related responsibilities leaders in innovative SMEs have when preparing employees prior to M&As in order to mitigate drawbacks due to culturally related discrepancies. The findings of this study especially confirm previous studies on culturally related difficulties in change management by emphasising the significant meaning of evaluating soft factors prior to change. The study was conducted by examining an innovative SME in the telecom industry that...

Rasmussen, Sara

2013-01-01

276

A comparison of cytokine production in 2-dimensional and 3-dimensional cultures of bone marrow stromal cells of multiple myeloma patients in response to RPMI8226 myeloma cells.  

Directory of Open Access Journals (Sweden)

Full Text Available We examined cytokine production by bone marrow stromal cells (BMSCs of patients with multiple myeloma (MM in response to contact with myeloma RPMI8226 cells in standard 2-dimensional (2D cultures and in 3-dimensional (3D cultures on a gelatine sponge scaffold. It was detected that BMSCs in the 3D cultures produced more IL-11 and HGF and less IL-10 than in the 2D cultures. Moreover, RPMI8226 cells after contact with BMSCs in 3D cultures produced more sIL-6R than in the classic 2D cultures. We concluded that 3D cultures of BMSCs with myeloma cells offered a promising model for in vitro examination of interactions between myeloma cells and the bone marrow stroma and for examination of potent antimyeloma agents.

Jacek Roli?ski

2009-05-01

277

Doxorubicin induces the DNA damage response in cultured human mesenchymal stem cells  

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Anthracyclines, including doxorubicin, are widely used in the treatment of leukemia. While the effects of doxorubicin on hematopoietic cells have been characterized, less is known about the response of human mesenchymal stem cells (hMSCs) in the bone marrow stroma to anthracyclines. We characterized the effect of doxorubicin on key DNA damage responses in hMSCs, and compared doxorubicin sensitivity and DNA damage response activation between isolated hMSCs and the chronic myelogenous leukemia ...

Cruet-hennequart, Sverine; Prendergast, A?ine M.; Shaw, Georgina; et al.

2012-01-01

278

Lactogenic response of cultured mouse mammary epithelial cells to mouse placental lactogen.  

Science.gov (United States)

The ability of mouse placental lactogen (mPL), mouse prolactin (mPRL), mouse GH (mGH) and ovine prolactin (oPRL) to stimulate synthesis of alpha-lactalbumin was tested in a primary culture of mouse mammary gland epithelial cells. Mammary tissue was obtained from 10-day pregnant Swiss Webster mice, enzymatically dissociated and the cells were cultured on floating collagen gels for 5 days. The basic culture medium consisted of Nutrient Mixture F12/Dulbecco's Modified Eagle's Medium (1:1, v/v), containing 10 mg insulin/1, 5 mg cortisol/l, 10 micrograms epidermal growth factor/l, 5 g bovine serum albumin/l and 50 mg gentamycin/l. Mouse PL, mPRL, mGH and oPRL were added to the basic medium in concentrations from 1 microgram/l to 1 mg/l. Accumulation of alpha-lactalbumin in the culture medium was measured. For that purpose, mouse alpha-lactalbumin was purified from mammary tissue obtained from lactating Swiss Webster mice and a radioimmunoassay was developed. Mouse PL, mPRL and oPRL stimulated a dose-dependent increase in alpha-lactalbumin secretion. Mouse GH also caused a significant, but dose-independent, increase in alpha-lactalbumin secretion. Mouse PL showed the greatest activity in stimulating alpha-lactalbumin secretion. It was concluded that mPL is an important lactogenic hormone in the latter half of pregnancy in the mouse, when circulating mPRL concentrations are low. PMID:3711764

Thordarson, G; Villalobos, R; Colosi, P; Southard, J; Ogren, L; Talamantes, F

1986-05-01

279

Developing a Culturally Responsive Breast Cancer Screening Promotion with Native Hawaiian Women in Churches  

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This article presents findings from research to develop the promotional component of a breast cancer screening program for Native Hawaiian women associated with historically Hawaiian churches in medically underserved communities. The literature on adherence to health recommendations and health promotions marketing guided inquiry on screening influences. Focus groups and individual interviews patterned on the culturally familiar practice of talk story were conducted with 60 Hawaiian women recr...

Ka’opua, Lana Sue

2008-01-01

280

Enhanced triterpene production in Tabernaemontana catharinensis cell suspension cultures in response to biotic elicitors  

Directory of Open Access Journals (Sweden)

Full Text Available Cell suspension cultures of Tabernaemontana catharinensis were treated with autoclaved homogenates of Candida albicans, Fusarium oxysporum, Penicillium avelanium and Saccharomyces cerevisiae. The effects caused by the concentration, exposure time and the type of elicitor on the accumulation of pentacyclic triterpenes were monitored. When exposed to biotic elicitors for longer periods, some cell lines redoubled the production of those triterpenes. Saccharomyces cerevisiae homogenate was the best elicitor of triterpenes in all cell lines investigated.

Paulo Sérgio Pereira

2007-01-01

 
 
 
 
281

Acute neuregulin-1 signaling influences AMPA receptor mediated responses in cultured cerebellar granule neurons  

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Neuregulin-1 (NRG1) is a trophic and differentiation factor that signals through ErbB receptor tyrosine kinases to regulate nervous system development. Previous studies have demonstrated that NRG1 affects plasticity at glutamatergic synapses in principal glutamatergic neurons of the hippocampus and frontal cortex; however, immunohistochemical and genetic analyses strongly suggest these effects are indirect and mediated via ErbB4 receptors on GABAergic interneurons. Here, we used cultured cere...

Fenster, Catherine; Vullhorst, Detlef; Buonanno, Andres

2012-01-01

282

Response of cultured mammalian cells to x-rays and ultraviolet light  

International Nuclear Information System (INIS)

As a part of the study of some of the known carcinogenic environmental agents as mutagens on mammalian cells in culture, sensitivity of chinese hamster cells (male, lung) to X-rays and ultraviolet light has been investigated. The results indicated that the pretreatment of cells with one of the radiations sensitizes them to the other in terms of both viability and mutation induction. (M.G.B.)

1978-10-01

283

Banking culture and collective responsibility: A memorandum to the UK Parliamentary Commission on Banking Standards  

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Basic assumptions • There is wide interest in connecting issues of (i) occupational culture, (ii) compliance/ misconduct, (iii) remuneration and (iv) clawback (the bonus/malus debate). • Individual-focussed measures (supervision, remuneration and measures in civil or criminal law) must be supplemented by a wider, whole-firm regulatory strategy. • Whilst attention has been drawn to ‘the tone at the top’, ‘the tone in the middle’ and ‘the tone at the bottom’ are as important. ...

Dorn, N.

2013-01-01

284

Microglial responses to dopamine in a cell culture model of Parkinson’s disease  

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Activated microglia appear to selectively attack dopamine (DA) neurons in the Parkinson’s disease (PD) substantia nigra. We investigated potential mechanisms using culture models. As targets, human SH-SY5Y cells were left undifferentiated, or were differentiated with retinoic acid (RA) or RA plus brain-derived neurotrophic factor (RA/BDNF). RA/BDNF-treated cells were immunoreactive for tyrosine hydroxylase and the DA transporter, took up exogenous DA, and released DA after K+ stimulation. U...

Mastroeni, Diego; Grover, Andrew; Leonard, Brian; Joyce, Jeffrey N.; Coleman, Paul D.; Kozik, Brooke; Bellinger, Denise L.; Rogers, Joseph

2009-01-01

285

Neutral lipid content and biomass production in Skeletonema marinoi (Bacillariophyceae) culture in response to nitrate limitation.  

Science.gov (United States)

Microalgae are one of the most promising biodiesel feedstocks due to their efficiency in CO2 fixation and high neutral lipid productivity. Nutrient-stress conditions, including nitrogen starvation, enhance neutral lipid content, but at the same time lead to a reduction of biomass. To maximize lipid production in the diatom Skeletonema marinoi, we investigated two different nitrogen starvation approaches. In the first experimental approach, inocula were effectuated in modified f/2 media with decreasing nitrogen concentration, while in the second experiment, nitrate concentration was gradually reduced through a collection/resuspension system in which the culture was periodically collected and resuspended in culture medium with a lower nitrate concentration. In the first approach, the neutral lipid accumulation was accompanied by a strong biomass reduction, as was expected, whereas the second experiment generated cultures with significantly higher neutral lipid content without affecting biomass production. The total proteins and total carbohydrates, which were also quantified in both experiments, suggest that in S. marinoi, neutral lipid accumulation during nutrient starvation did not derive from a new carbon partition of accumulated carbohydrates. PMID:23712793

Bertozzini, Elena; Galluzzi, Luca; Ricci, Fabio; Penna, Antonella; Magnani, Mauro

2013-08-01

286

Regulation of gonadotropin receptors, gonadotropin responsiveness, and cell multiplication by somatomedin-C and insulin in cultured pig Leydig cells  

Energy Technology Data Exchange (ETDEWEB)

The author have investigated the effects of insulin and somatomedin-C/insulin like growth factor I(Sm-C) in purified porcine Leydig cells in vitro on gonadotrophins (hCG) receptor number, hCG responsiveness (cAMP and testosterone production), and thymidine incorporation into DNA. Leydig cells cultured in a serum-free medium containing transferrin, vitamin E, and insulin (5 ..mu..g/ml) maintained fairly constant both hCG receptors and hCG responsiveness. When they were cultured for 3 days in the same medium without insulin, there was a dramatic decline (more than 80%) in both hCG receptor number and hCG responsiveness. However the cAMP but not the testosterone response to forskolin was normal. Both insulin and Sm-C at nanomolar concentrations prevent the decline of both hCG receptors and hCG-induced cAMP production. At nanomolar concentrations, Sm-C and insulin enhanced hCG-induced testosterone production but the effect of Sm-C was significantly higher than that of insulin. However, the effect of insulin at higher concentrations (5 ..mu..g/ml) was significantly higher than that of Sm-C at 50 ng/ml. In contrast, at nanomolar concentrations only Sm-C stimulated (/sup 3/H)-thymidine incorporation into DNA and cell multiplication, the stimulatory effect of insulin on these parameters, was seen only at micromolar concentrations. These results indicate that both Sm-C and insulin acting through the receptors increase Leydig cell steroidogenic responsiveness to hCG by increasing hCG receptor number and improving some step beyond cAMP formation. In contrast, the mitogenic effects of insulin are mediated only through Sm-C receptors.

Bernier, M.; Chatelain, P.; Mather, J.P.; Saez, J.M.

1986-11-01

287

Differential effect of culture epimastigotes and blood-form Trypamastigotes on normal mouse splenocyte responsiveness to mitogens  

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Blood form trypomastigotes of the Y strain of T. cruzi, produced a strong inhibition of the blastogenic response to T and B cell mitogens, of the C3H/He, C57BLand BALB/cJ strains of mice, while culture epimastigotes of the Y strain kept in a medium that allows parasite growth at 26°. 30° and 37°C produced a strong stimulatory effect that was even higher than the effect of the mitogens alone. Both the inhibitory or the stimulatory effects were dose-dependent. The stimulatory effect of epima...

1986-01-01

288

Rice improvement, involving altered flower structure more suitable to cross-pollination, using in vitro culture in combination with mutagenesis  

International Nuclear Information System (INIS)

Anther and somatic tissue culture in combination with mutagenesis were carried out to evaluate the efficiency of different mutagenic treatments of various in vitro culture materials, and to obtain some promising variants for rice improvement. Results indicated that in japonica rice radiation treatment of dry seeds and young panicles influenced the percentage of green plantlets regeneration from anther culture. Both treatments increased significantly the percentage of regenerated green plantlets in comparison with the control. Irradiation with 30 Gy of rice callus increased also the percentage of regenerated green plantlets. For indica rice, the combination of the suitable dose of gamma rays irradiation on seeds and an improved medium, increased the percentage of callus induction. This approach made it possible to use anther culture in indica rice breeding. Somatic tissue cultures combined with radiation-induced mutagenesis led to the development of a number of promising mutants including some new cytoplasm-nucleus interacting male-sterile lines with almost 100% stigma exertion. Their development would be of practical significance for increasing the genetic diversity for production of hybrid rice. (author)

1998-01-01

289

Evaluation of Rice (Oryza sativa L. Cultivars Response to Salinity Stress Through Greenhouse Experiment and Tissue Culture Technique  

Directory of Open Access Journals (Sweden)

Full Text Available The response to salinity stress of 4 rice cultivars was evaluated through a greenhouse experiment and a tissue culture technique at Agricultural College, Mazandaran University, Sari, Iran, during 2003. In the first experiment, carried out at seedling stage, three salinity levels (0, 75 and 150 mmol NaCl were used, pots arranged as a split plot based on completely randomized design with four replications and traits including seedling dry weight, wet weight, shoot length and root length were measured. In the second experiment, cultivars were callus induced trough the seed culture and calli placed in LS mediums containing four salinity levels (0, 75, 112.5 and 150 mmol NaCl. The experimental lay-out was factorial based on completely randomized design with 6 replications and callus volume of cultivars was measured according to Hooker and Nabors scale. The results indicated that all cultivars were influenced by increasing salinity level from 0 to 150 mmol NaCl in all traits. Tichung-65 distinguished the most salt-tolerant cultivar, showed the lowest reduction in evaluated traits by increasing salinity stress, whereas Tarom chaloosi was the salt-sensitive one. Moreover, cultivars including Tarom chaloosi and Binam chaloosi, exhibiting low salt tolerance characteristic in seedling stage generated tolerant calli through tissue culture technique as the salinity level increased from 0 to 150 mmol NaCl.

Sahab Rahmanzadeh

2008-01-01

290

Purification and partial characterisation of two abscisic-acid-responsive proteins induced in cultured embryos ofPisum sativum L.  

Science.gov (United States)

When pea (Pisum sativum L.) embryos were cultured on low osmotica, with or without added abscisic acid (ABA), there was very little change in the total mRNA translation products resolved by one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The only marked alteration was an increase in production of two low-molecular-weight proteins. The purification and partial characterisation of these two ABA-responsive seed proteins (ABR17 and ABR18) is described. Both proteins were purified to homoeneity, as judged by SDS-PAGE, from embryos cultured in the presence of ABA. Antisera were raised against both proteins. Each serum cross-reacted with the other protein, indicating that the proteins are closely related. Their apparent molecular masses (Mrs) were estimated to be 17200 (ABR17) and 18100 (ABR18) by SDS-PAGE, and 26000 by gel filtration. Both proteins were heterogeneous on isoelectric focusing. Neither protein was detected (by immunoblotting or immunoprecipitation of cell-free translation products) in embryos grown in vivo at early to mid-development stages but both were present in embryos late in development. These proteins appear to be produced late in seed development but are capable of being induced early in development by culturing embryos in vitro and are markedly enhanced by ABA. PMID:24201839

Barratt, D H; Domoney, C; Wang, T L

1989-12-01

291

The anther smut disease on Gypsophila repens: a case of parasite sub-optimal performance following a recent host shift?  

Science.gov (United States)

The study of how parasites adapt to new hosts is of great importance for understanding the emergence of new diseases. Here, we report a study of the anther smut disease on Gypsophila repens (Caryophyllaceae). In contrast to what is usually found on other host species, infected natural populations of G. repens are extremely rare. Moreover, symptoms of diseased plants are incomplete and highly variable over the time. These results suggest that the fungus infecting G. repens is a case of a parasite not capable of exploiting its host optimally. Molecular analyses of Microbotryum violaceum strains infecting this and other Caryophyllaceae revealed that this sub-optimal behaviour probably resulted from a recent host shift from the morphologically similar plant Petrorhagia saxifraga. With its exceptionally low virulence and prevalence, but apparent self-sustainability, the disease on G. repens may thus represent an interesting case study for investigating the conditions leading to adaptation of parasites on new hosts. PMID:16135124

López-Villavicencio, M; Enjalbert, J; Hood, M E; Shykoff, J A; Raquin, C; Giraud, T

2005-09-01

292

Age and dose related alteration of in vitro mixed lymphocyte culture response of blood lymphocytes from A-bomb survivors  

International Nuclear Information System (INIS)

The responsiveness of peripheral blood lymphocytes to allogenic antigens in mixed lymphocyte culture (MLC) was measured in 139 atomic-bomb survivors. The study revealed a significant decrease in MLC response with increasing dose of previous radiation exposure. This decline was marked in the survivors who were older than 15 at the time of the bomb (ATB). The results suggest a possible relationship between the recovery of T-cell-related function and the thymic function which processes mature T cells for the immune system. Thus it may be that in the advanced age ATB group, the thymus function had started to involute, allowing less recovery of T-cell function compared to young survivors who had adequate processing T-cell activity

1989-01-01

293

Immune response to purified chick embryo cell culture rabies vaccine (Rabipur) in dog-bite victims.  

Science.gov (United States)

The immunogenic and protective efficacy of a new, killed and purified rabies virus vaccine prepared in chick embryo fibroblast cell culture, has been evaluated. Vaccine was administered on days 0, 3, 7, 14, 30 and 90 to 29 subjects who were bitten by dogs. Persons bitten on the face, neck or hand were also given rabies immunoglobulin. Virus neutralizing antibody was measured on serially collected sera. On day 14, all 26 subjects who were tested had developed protective levels of antibody. High levels of antibody were maintained through day 105. No adverse reactions to the vaccine was reported by the subjects. PMID:2807425

Selvakumar, R; John, T J

1989-07-01

294

Heterogeneity of muscarinic receptor-mediated Ca2+ responses in cultured urothelial cells from rat  

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Muscarinic receptors (mAChRs) have been identified in the urothelium, a tissue that may be involved in bladder sensory mechanisms. This study investigates the expression and function of mAChRs using cultured urothelial cells from the rat. RT-PCR established the expression of all five mAChR subtypes. Muscarinic agonists acetylcholine (ACh; 10 ?M), muscarine (Musc; 20 ?M), and oxotremorine methiodide (OxoM; 0.001–20 ?M) elicited transient repeatable increases in the intracellular calcium c...

Kullmann, F. Aura; Artim, D.; Beckel, J.; Barrick, S.; Groat, W. C.; Birder, L. A.

2008-01-01

295

Acute neuregulin-1 signaling influences AMPA receptor mediated responses in cultured cerebellar granule neurons.  

Science.gov (United States)

Neuregulin-1 (NRG1) is a trophic and differentiation factor that signals through ErbB receptor tyrosine kinases to regulate nervous system development. Previous studies have demonstrated that NRG1 affects plasticity at glutamatergic synapses in principal glutamatergic neurons of the hippocampus and frontal cortex; however, immunohistochemical and genetic analyses strongly suggest these effects are indirect and mediated via ErbB4 receptors on GABAergic interneurons. Here, we used cultured cerebellar granule cells (CGCs) that express ErbB4 to analyze the cell-autonomous effects of NRG1 stimulation on glutamatergic function. These cultures have the advantage that they are relatively homogenous and consist primarily of granule neurons that express ErbB4. We show that acute NRG1 treatment does not affect whole-cell AMPA or NMDA receptor (NMDAR) mediated currents in CGCs at 10-12 days in vitro. NRG1 also does not affect the frequency or amplitude of spontaneous AMPAR or NMDAR mediated miniature excitatory post-synaptic currents (mEPSCs). To further investigate the effects of NRG1 on activity-dependent plasticity of glutamatergic synapses in CGCs, we characterized the effects of high-glyine/0 Mg(2+) (which activates synaptic NMDARs) on AMPAR-mEPSC frequency and amplitude. We show that high-glycine induces a form of chemical long-term potentiation (chemLTP) in CGCs characterized by an increase in AMPAR-mEPSC frequency but not amplitude. Moreover, NRG1 induces a decrease in AMPAR-mEPSC frequency following chemLTP, but does not affect AMPAR-mEPSC amplitude. CGCs in our cultures conditions express low levels of GluR1, in contrast to dissociated hippocampal cultures, but do express the long isoform of GluR4. This study provides first evidence that (1) high-glycine can induce plasticity at glutamatergic synapses in CGCs, and (2) that acute NRG1/ErbB-signaling can regulate glutamatergic plasticity in CGCs. Taken together with previous reports, our results suggest that, similar to Schaeffer collateral to CA1 synapses, NRG1 effects are activity dependent and mediated via modulation of synaptic AMPARs. PMID:22044943

Fenster, Catherine; Vullhorst, Detlef; Buonanno, Andres

2012-01-01

296

Polyamine Oxidase 7 is a Terminal Catabolism-Type Enzyme in Oryza sativa and is Specifically Expressed in Anthers.  

Science.gov (United States)

Polyamine oxidase (PAO), which requires FAD as a cofactor, functions in polyamine catabolism. Plant PAOs are classified into two groups based on their reaction modes. The terminal catabolism (TC) reaction always produces 1,3-diaminopropane (DAP), H2O2, and the respective aldehydes, while the back-conversion (BC) reaction produces spermidine (Spd) from tetraamines, spermine (Spm) and thermospermine (T-Spm) and/or putrescine from Spd, along with 3-aminopropanal and H2O2. The Oryza sativa genome contains seven PAO-encoded genes termed OsPAO1-OsPAO7. To date, we have characterized four OsPAO genes. The products of these genes, i.e. OsPAO1, OsPAO3, OsPAO4 and OsPAO5, catalyze BC-type reactions. Whereas OsPAO1 remains in the cytoplasm, the other three PAOs localize to peroxisomes. Here, we examined OsPAO7 and its gene product. OsPAO7 shows high identity to maize ZmPAO1, the best characterized plant PAO having TC-type activity. OsPAO7 seems to remain in a peripheral layer of the plant cell with the aid of its predicted signal peptide and transmembrane domain. Recombinant OsPAO7 prefers Spm and Spd as substrates, and it produces DAP from both substrates in a time-dependent manner, indicating that OsPAO7 is the first TC-type enzyme identified in O. sativa. The results clearly show that two types of PAOs co-exist in O. sativa. Furthermore, OsPAO7 is specifically expressed in anthers, with an expressional peak at the bicellular pollen stage. The physiological function of OsPAO7 in anthers is discussed. PMID:24634478

Liu, Taibo; Kim, Dong Wook; Niitsu, Masaru; Maeda, Shunsuke; Watanabe, Masao; Kamio, Yoshiyuki; Berberich, Thomas; Kusano, Tomonobu

2014-06-01

297

Salmonella Typhimurium Type III Secretion Effectors Stimulate Innate Immune Responses in Cultured Epithelial Cells  

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Recognition of conserved bacterial products by innate immune receptors leads to inflammatory responses that control pathogen spread but that can also result in pathology. Intestinal epithelial cells are exposed to bacterial products and therefore must prevent signaling through innate immune receptors to avoid pathology. However, enteric pathogens are able to stimulate intestinal inflammation. We show here that the enteric pathogen Salmonella Typhimurium can stimulate innate immune responses i...

2009-01-01

298

Effects of culture conditions on estrogen-mediated hepatic in vitro gene expression and correlation to in vivo responses  

International Nuclear Information System (INIS)

Refinement of in vitro systems for predictive toxicology is important in order to develop high-throughput early toxicity screening assays and to minimize animal testing studies. This study assesses the ability of mouse Hepa-1c1c7 hepatoma cell model under differing culture conditions to predict in vivo estrogen-induced hepatic gene expression changes. Custom mouse cDNA microarrays were used to compare Hepa-1c1c7 temporal gene expression profiles treated with 10 nM 17?-estradiol (E2) in serum-free and charcoal-stripped serum supplemented media at 1, 2, 4, 8, 12, and 24 h. Stripped serum supplemented media increased the number gene expression changes and overall responsiveness likely due to the presence of serum factors supporting proliferation and mitochondrial activity. Data from both experiments were compared to a gene expression time course study examining the hepatic effects of 100 ?g/kg 17?-ethynyl estradiol (EE) in C57BL/6 mice at 2, 4, 8, 12, 18, and 24 h. Only 18 genes overlapped between the serum-free and in vivo studies, whereas 238 genes were in common between Hepa-1c1c7 cells in stripped serum data and C57BL/6 liver samples. Stripped serum cultured cells exhibited E2-elicited gene expression changes associated with proliferation, cytoskeletal re-organization, cholesterol uptake and synthesis, increased fatty acid ?-oxidation, and oxidative stress, which correlated with in vivo hepatic responses. These results demonstrate that E2 treatment of Hepa-1c1c7 cells in serum supplemented media modulate responses in selected pathways which appropriately model estrogen-elicited in vivo hepatic responses

2006-08-15

299

Characterization of [Ca2+]i responses in primary cultures of mouse cardiomyocytes induced by Trypanosoma cruzi trypomastigotes  

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Full Text Available Trypanosoma cruzi, the protozoan responsible for Chagas disease, employs distinct strategies to invade mammalian host cells. In the present work we investigated the participation of calcium ions on the invasion process using primary cultures of embryonic mice cardiomyocytes which exhibit spontaneous contraction in vitro. Using Fura 2-AM we found that T. cruzi was able to induce a sustained increase in basal intracellular Ca2+ level in heart muscle cells (HMC, the response being associated or not with Ca2+ transient peaks. Assays performed with both Y and CL strains indicated that the changes in intracellular Ca2+ started after parasites contacted with the cardiomyocytes and the evoked response was higher than the Ca2+ signal associated to the spontaneous contractions. The possible role of the extracellular and intracellular Ca2+ levels on T. cruzi invasion process was evaluated using the extracellular Ca2+ chelator EGTA alone or in association with the calcium ionophore A23187. Significant dose dependent inhibition of the invasion levels were found when intracellular calcium release was prevented by the association of EGTA +A23187 in calcium free medium. Dose response experiments indicated that EGTA 2.5 mM to 5 mM decreased the invasion level by 15.2 to 35.1% while A23187 (0.5 µM alone did not induce significant effects (17%; treatment of the cultures with the protease inhibitor leupeptin did not affect the endocytic index, thus arguing against the involvement of leupeptin sensitive proteases in the invasion of HMC.

Garzoni Luciana R

2003-01-01

300

Characterization of [Ca2+]i responses in primary cultures of mouse cardiomyocytes induced by Trypanosoma cruzi trypomastigotes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Trypanosoma cruzi, the protozoan responsible for Chagas disease, employs distinct strategies to invade mammalian host cells. In the present work we investigated the participation of calcium ions on the invasion process using primary cultures of embryonic mice cardiomyocytes which exhibit spontaneous [...] contraction in vitro. Using Fura 2-AM we found that T. cruzi was able to induce a sustained increase in basal intracellular Ca2+ level in heart muscle cells (HMC), the response being associated or not with Ca2+ transient peaks. Assays performed with both Y and CL strains indicated that the changes in intracellular Ca2+ started after parasites contacted with the cardiomyocytes and the evoked response was higher than the Ca2+ signal associated to the spontaneous contractions. The possible role of the extracellular and intracellular Ca2+ levels on T. cruzi invasion process was evaluated using the extracellular Ca2+ chelator EGTA alone or in association with the calcium ionophore A23187. Significant dose dependent inhibition of the invasion levels were found when intracellular calcium release was prevented by the association of EGTA +A23187 in calcium free medium. Dose response experiments indicated that EGTA 2.5 mM to 5 mM decreased the invasion level by 15.2 to 35.1% while A23187 (0.5 µM) alone did not induce significant effects (17%); treatment of the cultures with the protease inhibitor leupeptin did not affect the endocytic index, thus arguing against the involvement of leupeptin sensitive proteases in the invasion of HMC.

Luciana R, Garzoni; Masako Oya, Masuda; Márcia M, Capella; Anibal Gil, Lopes; Maria de Nazareth S Leal de, Meirelles.

 
 
 
 
301

Comparative study of proliferation of suckling and adult rat hepatocytes in primary culture in response to growth-stimulating factors.  

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Full Text Available The replicative responses of suckling and adult rat hepatocytes in primary culture to growth-stimulating factors were compared. By addition of L-proline alone, the [3H]-thymidine labeling of suckling rat hepatocytes was dramatically enhanced, but that of adult ones was not. Epidermal growth factor (EGF, insulin, triiodothyronine (T3 and glucagon also enhanced the labeling of suckling rat hepatocytes regardless of the presence or the absence of L-proline. On the other hand, in the absence of L-proline, only EGF enhanced the labeling of adult rat hepatocytes, and, in the presence of L-proline, insulin as well as EGF enhanced the labeling. In the presence of growth factors and L-proline, the number of suckling rat hepatocytes increased up to about 143%, whereas that of adult rat hepatocytes hardly increased. Thus, a remarkable difference in replicative responses to growth factors and L-proline was observed between suckling and adult rat hepatocytes in primary culture.

Handa,Yoshihiko

1986-12-01

302

Dimethyl sulfoxide is a potent modulator of estrogen receptor isoforms and xenoestrogen biomarker responses in primary culture of salmon hepatocytes  

International Nuclear Information System (INIS)

Dimethyl sulfoxide (DMSO) has been frequently used as carrier solvent in toxicological experiments where the most compelling DMSO attributes are its exceptionally low toxicity and environmental impact. We were inspired by recent and consistent observations that ethanol and DMSO modulate endocrine-disruptor biomarker responses in both in vitro and in vivo studies in our laboratory, to take a critical evaluation of these effects. Quantitative (real-time) polymerase chain reaction (PCR) method with specific primer pairs was used in this study to measure DMSO-induced time-dependent modulation of estrogen receptor (ER) isoforms, vitellogenin (Vtg) and zona radiata-protein (Zr-protein) gene expression patterns in primary culture of salmon hepatocytes. In addition, immunochemical analysis, using indirect enzyme linked immunosorbent assay (ELISA) with monoclonal (Vtg) and polyclonal (Zr-proteins) antibodies was used to detect and measure Vtg and Zr-proteins secreted in culture media. Salmon hepatocytes were isolated by a two-step collagenase perfusion method and exposed to 0.1% or 10 ?L/L of DMSO after 48 h pre-culture. Cells were harvested at 12, 24, 48 and 72 h after exposure and analysed for ER?, ER?, Vtg and Zr-protein gene expression using real-time PCR method. Media samples were collected at similar time-intervals for protein analysis. Our data show that DMSO-induced significant increase in ER?, ER?, Vtg and Zr-protein genes in a time-dependent manner. Indirect ELISA analysis showed a time-specific effect of DMSO. The use of DMSO as carrier solvent in fish endocrine disruption studies should be re-evaluated. We recommend more investigation, using other endocrine-disruptor biomarkers in order to validate the suitability of common carrier solvents used in toxicology with the aim of setting new maximum allowable concentrations. In particular, given the high sensitivity of genomic approaches in toxicology, these results may have serious consequences for the interpretation of biomarker responses

2006-08-12

303

PULEX: influence of environment radiation background on biochemistry and biology of cultured cells and on their response to genotoxic agents  

International Nuclear Information System (INIS)

Some years ago we performed two experiments aimed at studying the influence of the background radiation on living matter by exploiting the low radiation background environment in the underground Gran Sasso Laboratory of the INFN Their results were consistent with the hypothesis that the normal background radiation determines an adaptive response, although they cannot be considered conclusive. PULEX-3 (the third experiment of the series) is aimed at comparing the effects of different background radiation environments on metabolism of cultured mammalian cells, with substantial improvements with respect to the preceding ones. The experiment was designed to minimize variabilities, by maintaining two cultures of Chinese hamster V79 cells in exponential growth for up to ten months in the underground Gran Sasso Laboratory (LNGS), while two other cultures were maintained in parallel in a biological laboratory installed at the LNGS outside the tunnel. Exposure due to ?-rays was reduced by a factor of about 10 in the underground laboratory while the Rn concentration was small in both cases. After ten months the cells grown in the underground laboratory, compared to those grown in the external one, exhibited: 1) a significantly lower capacity to scavenge reactive oxygen species (ROS). and 2) an increased sensitivity to the mutagenic effect of rays Since the probability that this finding is due to casual induction of radiosensitive mutants is extremely low, it corroborates the hypothesis that cells grown in a normal background radiation environment exhibit an adaptive response when challenged with genotoxic agents, which is lost after many generations in a low background radiation environment.

2008-01-01

304

Acid-growth response and alpha-expansins in suspension cultures of bright yellow 2 tobacco  

Science.gov (United States)

The possibility that Bright Yellow 2 (BY2) tobacco (Nicotiana tabacum L.) suspension-cultured cells possess an expansin-mediated acid-growth mechanism was examined by multiple approaches. BY2 cells grew three times faster upon treatment with fusicoccin, which induces an acidification of the cell wall. Exogenous expansins likewise stimulated BY2 cell growth 3-fold. Protein extracted from BY2 cell walls possessed the expansin-like ability to induce extension of isolated walls. In western-blot analysis of BY2 wall protein, one band of 29 kD was recognized by anti-expansin antibody. Six different classes of alpha-expansin mRNA were identified in a BY2 cDNA library. Northern-blot analysis indicated moderate to low abundance of multiple alpha-expansin mRNAs in BY2 cells. From these results we conclude that BY2 suspension-cultured cells have the necessary components for expansin-mediated cell wall enlargement.

Link, B. M.; Cosgrove, D. J.

1998-01-01

305

The influence of exogenous eicosanoids on the radiation response of cultured bovine aortic endothelial cells  

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The radioprotection by several eicosanoids was investigated in cultures of bovine aortic endothelial cells. One hour before irradiation (0-500 cGy, 137Cs gamma rays) 10 micrograms/ml of PGD2, PGE1, PGI2, misoprostol (PGE1-analog), 16,16-dimethyl PGE2, PGA2, or 1 microgram/ml LTC4 was added. Radiation decreased incorporation of (3H)thymidine at 4 h, cell number/culture at 24 h, and cell survival as measured by colony formation. Under these conditions the eicosanoids were not radioprotective. Two eicosanoids, PGD2 and PGA2, appeared to be toxic. Because receptors might mediate eicosanoid-induced radioprotection, radioligand binding of PGE2 and LTC4 and levels of adenosine 3',5'-cyclic monophosphate (cAMP) were measured. Evidence for a receptor was equivocal; there was nonspecific binding and metabolism of LTC4. The level of cAMP was elevated by 16-16-dimethyl-PGE2 in the presence of isobutyl methylxanthine; however, this combination of the prostaglandin and the methylxanthine was not radioprotective. These investigations suggest that an elevated cAMP level alone does not lead to eicosanoid-induced radioprotection of bovine aortic endothelial cell monolayers in vitro.

Rubin, D.B.; Drab, E.A.; Stone, A.M.; Walden, T.L. Jr.; Hanson, W.R. (Rush-Presbyterian-St. Luke' s-Medical Center, Chicago, IL (USA))

1991-01-01

306

The influence of exogenous eicosanoids on the radiation response of cultured bovine aortic endothelial cells  

International Nuclear Information System (INIS)

The radioprotection by several eicosanoids was investigated in cultures of bovine aortic endothelial cells. One hour before irradiation (0-500 cGy, 137Cs gamma rays) 10 micrograms/ml of PGD2, PGE1, PGI2, misoprostol (PGE1-analog), 16,16-dimethyl PGE2, PGA2, or 1 microgram/ml LTC4 was added. Radiation decreased incorporation of [3H]thymidine at 4 h, cell number/culture at 24 h, and cell survival as measured by colony formation. Under these conditions the eicosanoids were not radioprotective. Two eicosanoids, PGD2 and PGA2, appeared to be toxic. Because receptors might mediate eicosanoid-induced radioprotection, radioligand binding of PGE2 and LTC4 and levels of adenosine 3',5'-cyclic monophosphate (cAMP) were measured. Evidence for a receptor was equivocal; there was nonspecific binding and metabolism of LTC4. The level of cAMP was elevated by 16-16-dimethyl-PGE2 in the presence of isobutyl methylxanthine; however, this combination of the prostaglandin and the methylxanthine was not radioprotective. These investigations suggest that an elevated cAMP level alone does not lead to eicosanoid-induced radioprotection of bovine aortic endothelial cell monolayers in vitro

1991-01-01

307

Growth and enzymatic responses of phytopathogenic fungi to glucose in culture media and soil  

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Full Text Available The effect of inoculation of Aspergillus flavus, Fusarium verticillioides, and Penicillium sp. in Dystrophic Red Latosol (DRL and Eutroferric Red Latosol (ERL soils with or without glucose on the total carbohydrate content and the dehydrogenase and amylase activities was studied. The fungal growth and spore production in culture medium with and without glucose were also evaluated. A completely randomized design with factorial arrangement was used. The addition of glucose in the culture medium increased the growth rate of A. flavus and Penicillium sp. but not of F. verticillioides. The number of spores increased 1.2 for F. verticillioides and 8.2 times for A. flavus in the medium with glucose, but was reduced 3.5 times for Penicillium sp. The total carbohydrates contents reduced significantly according to first and second degree equations. The consumption of total carbohydrates by A. flavus and Penicillium sp. was higher than the control or soil inoculated with F. verticillioides. The addition of glucose to soils benefited the use of carbohydrates, probably due to the stimulation of fungal growth. Dehydrogenase activity increased between 1.5 to 1.8 times (p <0.05 in soils with glucose and inoculated with the fungi (except F. verticillioides, in relation to soil without glucose. Amylase activity increased 1.3 to 1.5 times due to the addition of glucose in the soil. Increased amylase activity was observed in the DRL soil with glucose and inoculated with A. flavus and Penicillium sp. when compared to control.

Beatriz de Oliveira Costa

2012-03-01

308

Growth and enzymatic responses of phytopathogenic fungi to glucose in culture media and soil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The effect of inoculation of Aspergillus flavus, Fusarium verticillioides, and Penicillium sp. in Dystrophic Red Latosol (DRL) and Eutroferric Red Latosol (ERL) soils with or without glucose on the total carbohydrate content and the dehydrogenase and amylase activities was studied. The fungal growth [...] and spore production in culture medium with and without glucose were also evaluated. A completely randomized design with factorial arrangement was used. The addition of glucose in the culture medium increased the growth rate of A. flavus and Penicillium sp. but not of F. verticillioides. The number of spores increased 1.2 for F. verticillioides and 8.2 times for A. flavus in the medium with glucose, but was reduced 3.5 times for Penicillium sp. The total carbohydrates contents reduced significantly according to first and second degree equations. The consumption of total carbohydrates by A. flavus and Penicillium sp. was higher than the control or soil inoculated with F. verticillioides. The addition of glucose to soils benefited the use of carbohydrates, probably due to the stimulation of fungal growth. Dehydrogenase activity increased between 1.5 to 1.8 times (p

Beatriz de Oliveira, Costa; Ely, Nahas.

309

Calcium-mediated enhancement of the cyclic AMP response in cultured bone cells.  

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We have examined the influence of extracellular Ca2+ on cyclic AMP metabolism in an osteoblast-enriched population of bone cells isolated from the calvaria of rat fetuses. The cyclic AMP response to stimulators of cyclic AMP formation (PTH and PGE2), but not basal cyclic AMP levels, increased progressively as the extracellular Ca2+ concentration was raised from 0.2 to 4.0 mM. The response to changes in extracellular Ca2+ were rapid (within 3.5 min), and the level of responsivity that characterized each Ca2+ concentration persisted for at least 6 h when the Ca2+ concentration was kept constant. The effect of Ca2+ spanned the entire time course of PTH action, was not accompanied by altered excretion of cyclic AMP from the cells, and was evident at low as well as at high hormone concentrations. Ca2+ augmented the action of PTH in the presence as well as in the absence of cyclic AMP phosphodiesterase inhibitors, and failed to decrease cyclic AMP phosphodiesterase activity in the short term. Mn2+ and, to a smaller degree, Ba2+ substituted for Ca2+ in promoting the cyclic AMP response to PTH. Verapamil, an inhibitor of Ca2+ penetration, blunted the Ca2+-mediated increments in the cyclic AMP response, and the divalent cation ionophore A23187 enhanced these increments. These results indicate that Ca2+ and other cations are positive effectors of the stimulated cyclic AMP response in isolated bone cells. Accumulation into an as yet unknown cellular compartment may be required for the cation effect. The data are most consistent with enhancement of adenylate cyclase reactivity as the mode of cation action. PMID:6271356

Peck, W A; Kohler, G; Barr, S

1981-01-01

310

Response of Grape Explants (cv. Bidaneh Soltani to Different Culture Media  

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Full Text Available To study the effects of different combinations of auxin (IBA, NAA and cytokinin (BAP, TDZ regulators, basal salts (MS, WPM, NN and gelling agents (Gelrite and Plant Agar on the growth and development of seedless grape explants (cv. Bidaneh Soltani, a factorial experiment was conducted based on a completely randomized design. The number and length of grown shoots were analyzed as two main characteristics. Growth regulators and salts had significant effects (at %1 on the shoot proliferation. The highest number of shoots was observed on MS salts combined with BAP (2.2 mg/l and IBA (0.5 mg/l on the 18th days of culture. Compared to Plant Agar, Gelrite had a better effect on the normal growth of the shoots. Based on the new shoots, combinations of MS salts and hormones may be used for micropropagation of seedless grape cultivars in the in vitro condition.

GH. Garousi

2008-10-01

311

Does culture matter?: a cross-national investigation of women's responses to cancer prevention campaigns.  

Science.gov (United States)

We examined how culture influences the persuasive effects of health campaigns that promote early screening for cancers that occur in women. Two message dimensions were included: individualistic vs. collectivistic appeal and gain vs. loss frame. A total of 955 females from three countries-the United States, South Korea, and Japan-participated in the experiment. From the results, we found that message framing alone did not significantly influence the effectiveness of public campaigns for women's cancer prevention; and this tendency was similar across the three countries. Gain-framed messages are likely to be more persuasive when combined with a collectivistic appeal, however, whereas loss-framed messages tend to be more effective when combined with an individualistic appeal in both the United States and South Korea; but this result was not the case for Japan. Based on the findings, we suggested theoretical and managerial implications as well as several directions for future research. PMID:22150267

Han, Kyoo-Hoon; Jo, Samsup

2012-01-01

312

Fish cell cultures as in vitro models of inflammatory responses elicited by immunostimulants. Expression of regulatory genes of the innate immune response.  

Science.gov (United States)

We report the differential expression of various genes related to the regulation of the innate immune responses, including pro-inflammatory (IL-1?1, IL-8, TNF-?1, TNF-?2) and immune-suppressing (IL-10) cytokines, interferon-induced Mx-1 protein, enzymes regulating nitric oxide (inducible nitric oxide synthase, arginase-2) and eicosanoid (COX-2) production, and Toll-like pathogen pattern-recognition receptors TLR-3, TLR-5 and TLR-9, in two lympho-haematopoietic stromal cell lines derived from the spleen (trout splenic stroma, TSS) and the pronephros (trout pronephric stroma-2, TPS-2) of rainbow trout (Oncorhynchus mykiss), as well as in primary cultures of rainbow trout head kidney macrophages, after their exposure to the well-known immunostimulants LPS, levamisole and poly I:C. Although there were differences in the responses between the two stromal cell lines, using reverse transcription followed by real time polymerase chain reaction (RT-qPCR) we demonstrated that exposure to the immunostimulants, particularly poly I:C and LPS, resulted in significant changes in the expression of the immunoregulatory genes in the two stromal cell lines in many cases their responses resembling in fold change magnitudes and in response profiles to those observed in the primary macrophage cultures. Exposure to poly I:C and, with lower fold change values, to LPS produced upregulation of the pro- (IL-1?, IL-8, TNF-?) and anti-inflammatory (IL-10) cytokine genes, as well as of the Mx-1 gene. Furthermore, the immunostimulation elicited the upregulation of COX-2, iNOS and arginase-2 genes in the cell lines. Likewise, the TSS and TPS-2 cell lines significantly upregulated the expression of TLR-3, TLR-5 and TLR-9 genes after exposure to the immunostimulants, thus explaining the ability of the stromal cells to recognise and respond to the immunostimulants. Such results give support to an important role of lympho-haematopoietic stromal cells in the development and control of pro-inflammatory responses in fish. The upregulation of genes of pro-inflammatory cytokines and of mediators of the innate immune responses correlates well with the previously demonstrated functional capacities, including phagocytosis, microbicidal activity and NO production, exhibited by the TSS and TPS-2 stromal cell lines when exposed to the same immunostimulants. On the other hand, the expression of immunosuppressing genes (IL-10, COX-2 and arginase-2) demonstrate that the lympho-haematopoietic stromal cells are also able to contribute to the control of inflammatory responses. This study reinforce the possibility of using histotypic cell cultures, as those formed by the TSS and TPS-2 cell lines, formed by heterogeneous cell populations that partially replicates the cell-cell and cell-extracellular matrix interactions, to develop cost-effective and repetitive in vitro systems for the screening of immunostimulant candidates for aquaculture, as they are able to replicate in vitro immune regulatory networks occurring in vivo. PMID:23872473

Fierro-Castro, C; Barrioluengo, L; López-Fierro, P; Razquin, B E; Villena, A J

2013-09-01

313

A culture-sensitive taxonomy of response tokens: moving from listnership to speakership  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis compares conversations between British tutors and British students, and conversations between British tutors and Japanese students, in English in order to investigate differences and similarities in their listenership behaviour in relation to the use of response tokens in the context of academic supervision sessions.

Tsuchiya, Keiko

2010-01-01

314

Multicultural Education Applications for Teachers of the Deaf: Creating Culturally Responsive Curriculum.  

Science.gov (United States)

This paper describes Project THREADS (Transformations for Humanistic and Responsive Education for All Deaf Students), a program to develop a model for increasing the multicultural competence of inservice teachers of the deaf. Project THREADS is designed to facilitate changes in individual teachers and changes in their institutions while working to…

deGarcia, Barbara Gerner

315

Cultural heritage  

Cultural heritage The Environment Agency??s role and responsibilities We take account of cultural heritage when carrying out our own works and activities. However, English Heritage, Cadw, and the Association of Local Government Archaeological Officers (See links below) are the contacts for this issue…

316

Reflexiones sobre la actualidad del relativismo cultural: respuesta a Nicolás Sánchez Durá / Considerations about the Pertinence of Cultural Relativism: Response to Nicolás Sánchez Durá  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish Este ensayo propone entablar una discusión con las tesis contenidas en el artículo de Nicolás Sánchez Durá, "Actualidad del relativismo cultural". En primer lugar, se analizan el etnocentrismo y el relativismo como dos respuestas éticas distintas al fenómeno de la diversidad cultural. En segundo lug [...] ar, se desarrollan la formulación del relativismo y el concepto de cultura propuestos por Sánchez Durá para analizarlos a la luz de la epistemología elaborada por el Wittgenstein tardío. En tercer lugar, se agregan argumentos a favor del relativismo cultural. El relativismo cultural, visto como una doctrina, tropieza con dilemas lógicos y conceptuales; considerado como una actitud contextual de índole moral y política, contribuye a combatir la autoridad del etnocentrismo basado en la exclusividad del otro. Abstract in english This essay proposes to develop and to discuss some thesis included in the article by Nicolás Sánchez Durá: "The Pertinence of Cultural Relativism". Firstly, the ethnocentric and relativistic positions are both considered as two different ethical attitudes towards the cultural diversity. Secondly, th [...] e concepts of "relativism" and "culture" are developed and analyzed in the light of Ludwig Wittgenstein's later philosophy. Although, the cultural relativism considered as a philosophical doctrine faces logical and conceptual dilemmas, the latter disappear when relativism is treated as contextual, mostly moral and political attitude, which contributes to undermine the legacy of ethno-centrism based on the other's exclusivity.

Jacorzynski, Witold.

317

The response of six cultured mammalian cells to hyperthermia and radiation  

International Nuclear Information System (INIS)

This review provides an update of studies for the understanding of fundamental process involved in the cellular responses to hyperthermia and radiation, which have been performed in the Research Institute for Nuclear Medicine and Biology, Hiroshima University. The studies cover (1) the comparison of intrinsic thermal and radiation sensitivities of individual cell lines; (2) kinetics of cell killing by hyperthermia; (3) the time course and mode of cell death; (4) cell-cycle dependent thermal sensitivity; (5) thermotolerance; (6) modifiers of thermal response-effect of membrane active agents; and (7) thermal radiosensitization. The data will provide some insight into the factors determining intrinsic thermosensitivity and the importance of the dye exclusion method as one of the approaches in elucidating intrinsic thermosensitivity and its relationship to the mechanisms and mode of heat-induced cell death in six different cell lines. 84 refs. (N.K.)

1991-01-01

318

The response of dark septate endophytes (DSE) to heavy metals in pure culture.  

Science.gov (United States)

Dark septate endophytes (DSE) occur widely in association with plants exposed to heavy metal stress. However, little is known about the response of DSE exposed to heavy metals. In this study, five DSE were isolated from the roots of Astragalus adsurgens Pall. seedlings growing on lead-zinc mine tailings in China. Based on morphological characteristics and DNA sequence analyses, the isolates were identified as Gaeumannomyces cylindrosporus, Paraphoma chrysanthemicola, Phialophora mustea, Exophiala salmonis, and Cladosporium cladosporioides. G. cylindrosporus was selected to explore responses to Pb stress. Scanning electron microscopic observations of G. cylindrosporus grown on solid medium revealed curling of hyphae and formation of hyphal coils in response to Pb. In contrast, in liquid medium, hyphae became thick and swollen with an increase in Pb (II) concentration. We interpret that these changes are related to the variation in cell wall components. We also demonstrated that fungal melanin content increased with the addition of Pb(II). Melanin, as an important component in the cell wall, is known to be an essential antioxidant responsible for decreasing heavy metal toxicity. We also measured the total soluble protein content and glutathione (GSH) concentrations in G. cylindrosporus and found that they initially increased and then decreased with the increase of Pb(II) concentrations. The antioxidant enzyme activities were also examined, and the results showed that superoxide dismutase (SOD) activity was significantly positively correlated with Pb(II) concentrations (r?=?0.957, P<0.001). Collectively, our observations indicate that the intracellular antioxidant systems, especially fungal melanin, play an important role in abating the hazards of heavy metals. PMID:23118914

Ban, Yihui; Tang, Ming; Chen, Hui; Xu, Zhouying; Zhang, Haihan; Yang, Yurong

2012-01-01

319

The Response of Dark Septate Endophytes (DSE) to Heavy Metals in Pure Culture  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dark septate endophytes (DSE) occur widely in association with plants exposed to heavy metal stress. However, little is known about the response of DSE exposed to heavy metals. In this study, five DSE were isolated from the roots of Astragalus adsurgens Pall. seedlings growing on lead-zinc mine tailings in China. Based on morphological characteristics and DNA sequence analyses, the isolates were identified as Gaeumannomyces cylindrosporus, Paraphoma chrysanthemicola, Phialophora mustea, Exoph...

2012-01-01

320

Optimization of culture conditions for exopolysaccharides production in Rhizobium sp. using the response surface method  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english The combined effects of the processing parameters for exopolysaccharides production by Rhizobium sp. was studied using the experimental design and response surface methodology. The experiments were carried out using a fermenter with 20 L capacity, as the reactor. All processing parameters were onlin [...] e monitored. The temperature [(30 ± 1)ºC] and pH value (7.0 ± 0.1) were kept constant throughout the experimental time. As statistical tools, a complete 2³ factorial planning with central point and response surface were used to study the interactions among three relevant variables of the fermentation process: calcium carbonate concentration, aeration and agitation. The processing parameters setup for reaching a maximum response for exopolysaccharides production was obtained when applying the highest values for calcium carbonate concentration (1.1 g/L), aeration (1.3 vvm) and agitation (800 rpm). In addition, the combination of these optimum processing parameters yielded Y P/S (g/g) = 0.35.

Flávia, Pereira Duta; Francisca, Pessôa de França; Léa Maria, de Almeida Lopes.

2006-07-15

 
 
 
 
321

Response of Bread Wheat Genotypes to Immature Embryo Culture, Callus Induction and Drought Stress  

Directory of Open Access Journals (Sweden)

Full Text Available In order to evaluate the response of twenty genotypes of bread wheat (Triticum aestivum L. to callus induction and in vitro drought stress. The immature embryos of wheat were used in a Completely Randomized Design (CRD with six replications for callus induction and a 20×2 factorial experiment based on CRD design with three replications was carried out for response of genotypes to in vitro drought stress at the Agricultural College of Razi University, Kermanshah, Iran during 2010-2011. Significant differences were observed among the genotypes for Callus Growth Rate (CGR, Relative Fresh Weight Growth (RFWG, Relative Growth Rate (RGR and Percentage of Callus Induction (PCI indicating the presence of genetic variability, different responses of bread wheat genotypes to callus induction and possible selection of callus induction at in vitro level using immature embryos. Mean comparison of the traits measured in callus induction showed that genotypes 1 and 6 had the highest PCI (100%. Analysis of variance for CGR, RFWG and RGR, Relative Water Content (RWC, Percent of Callus Chlorosis (PCC and Proline Content (PC exhibited significant differences among the genotypes for all the characters in the stress condition (15% PEG. Screening drought tolerant genotypes and in vitro indicators of drought tolerance using mean rank, standard deviation of ranks and biplot analysis, discriminated genotypes (6, (19 and (1 as the most drought tolerant.

Parvin Elyasi

2012-07-01

322

The university as an encounter for deliberative communication - creating cultural citizenship and professional responsibility  

Directory of Open Access Journals (Sweden)

Full Text Available How can higher and professional education contribute to the development of responsible citizenship and professional responsibility? In recent discussions on the role of the educational system, the idea of “deliberative communication” has been brought into focus and stands for communication in which different opinions and values can be set against each other in educational settings. It implies an endeavour by each individual to develop his or her view by listening, deliberating, seeking arguments and valuing, coupled to a collective and cooperative endeavour to find values and norms which everyone can accept, at the same time as pluralism is acknowledged. Within higher education deliberative communication might explicitly be used to develop professional responsibility and analysing consequences of different ways of solving problems. To what extent are and can universities become public spaces for encounters dealing with controversial questions of how to solve different problems and analyse different ways of professional acting? Can universities recreate their selective traditions, “institutionalize dissensus”, and “make the university a site of public debate” through deliberative communication?

Tomas Englund

2008-01-01

323

Evaluation of cytotoxic responses caused by selected organophosphorus esters in chick sympathetic ganglia cultures.  

Science.gov (United States)

Ten day old chick sympathetic ganglia cultured in a microslide assembly were treated with a selected group of organophosphate pesticides to evaluate their cytotoxicity ranges, and the usefulness of such a model for screening pesticides. Examination by phase contrast and light microscopy for chemically-induced morphological alteration of nerve fibers, glial cells and neurons provided the criteria for quantitation and assessment of the toxic effects. Concentrations that produced half-maximal effects ranged from 1 x 10(-6)M (severely toxic) for methylparathian, diazinon, paraoxon, mevinphos, diisopropylfluorophosphate, tri-o-tolyl phosphate and its mixed isomers to a 1 x 10(-3)M (intermediate) for malathion, leptophos, coumaphos, mono- and dicrotophos. Some or no effects were evident at 1 x 10(2-)M for O'ethyl-O-p-nitrophenyl phenyl phosphonothioate, tri-m-tolylphosphate, chlorpyriphos and triphenyl phosphate. In all instances, nerve fibers were more sensitive than neurons or glial cells to insecticides. All cellular growth was inhibited at 1 x 10(-2)M (except triphenyl phosphate). Below 1 x 10(-7)M, no inhibitory effects were evident. The secondary abnormalities included decreased cellular migration, diffuse cellular growth pattern, increased vacuolization, nerve fiber swelling and cellular degeneration. The cytotoxic effects of these chemicals do not appear to be related to in vivo toxicity or cholinesterase inhibition potential. PMID:565668

Obersteiner, E J; Sharma, R P

1978-01-01

324

Grape marc extract causes early perception events, defence reactions and hypersensitive response in cultured tobacco cells.  

Science.gov (United States)

Grape marc extract (GME) showed elicitor activity on suspension-cultured cells of tobacco. The BY-2 cells reacted to GME (0.25% and 0.125%) with a long-sustained pH rise in their growth medium. Using EGTA or LaCl3, we showed that extracellular alkalinization depended on Ca(2+) mobilization. The tobacco BY-2 cells challenged with GME promoted cell death and the upregulation of defence-related genes such as PR3, PAL and CCoAOMT. Cell death rate was quantified using an experimental calibrated Evans Blue assay. The GME-induced cell death was dose-dependent and occurred in 24 h. Longer exposure increased the extent of tobacco cell death. To investigate a potential hypersensitive reaction, we tested the effect of various inhibitors of protein synthesis (cycloheximide) and proteases (aprotinin, pepstatin and E-64) on GME-induced cell death. All these chemicals reduced GME-induced cell death rate in 30 min. Overall, our findings indicate that GME elicits early perception events, defence reactions and cell death requiring protein synthesis and proteases. PMID:24561714

Benouaret, R; Goujon, E; Goupil, P

2014-04-01

325

Interferon-modification of the in vitro radiation response in cultured human KNS-42 cells  

International Nuclear Information System (INIS)

The efficacy of combined interferon radiation therapy in cultured human KNS-42 glioma cells was examined. Beta-type human fibroblast interferon inhibited the multiplication of KNS-42 cells in a dose-dependent manner. The inhibitory effect was thought to be due to supression of the cells entering the S-phase. KNS-42 cells were treated with interferon before or after irradiation. The effect of the treatments was assayed by growth and survival curves. According to a cell growth analysis, the combined treatment had a greater anti-proliferative effect than the radiation or the interferon treatment alone. When interferon was given before irradiation, it tended to reduce the shoulder of the X-ray survival curve in a dose-dependent manner until the shoulder totally disappeared. The slope itself, however, was only moderately affected by interferon. The mechanism of this synergistic interaction between interferon and X-rays was possibly due to a partial synchronizing effect of interferon on the cells by blocking them in a G1/S boundary phase, the radiosensitive stage of the cell cycle. When interferon was given immediately after irradiation, it tended to reduce the slope in a dose-dependent manner. The shoulder disappeared almost totally even with a low dose of interferon. These results suggest that interferon may be useful as a radiosensitizing agent in tumor therapy. (author)

1984-01-01

326

Interferon-modification of the in vitro radiation response in cultured human KNS-42 cells  

Energy Technology Data Exchange (ETDEWEB)

The efficacy of combined interferon radiation therapy in cultured human KNS-42 glioma cells was examined. Beta-type human fibroblast interferon inhibited the multiplication of KNS-42 cells in a dose-dependent manner. The inhibitory effect was thought to be due to supression of the cells entering the S-phase. KNS-42 cells were treated with interferon before or after irradiation. The effect of the treatments was assayed by growth and survival curves. According to a cell growth analysis, the combined treatment had a greater anti-proliferative effect than the radiation or the interferon treatment alone. When interferon was given before irradiation, it tended to reduce the shoulder of the X-ray survival curve in a dose-dependent manner until the shoulder totally disappeared. The slope itself, however, was only moderately affected by interferon. The mechanism of this synergistic interaction between interferon and X-rays was possibly due to a partial synchronizing effect of interferon on the cells by blocking them in a G/sub 1//S boundary phase, the radiosensitive stage of the cell cycle. When interferon was given immediately after irradiation, it tended to reduce the slope in a dose-dependent manner. The shoulder disappeared almost totally even with a low dose of interferon. These results suggest that interferon may be useful as a radiosensitizing agent in tumor therapy. (author).

Korosue, Kazuyoshi; Tamaki, Norihiko; Matsumoto, Satoshi; Takeshita, Iwao; Fukui, Masashi

1984-04-01

327

Cellular responses in primary epidermal cultures from oncorhynchus mykiss following the combined exposure of ionising radiation and a heavy metal  

International Nuclear Information System (INIS)

Mechanisms of toxicant action on biological systems are difficult to identify when more than one contaminant is involved due to potential synergistic and antagonistic effects. There is a general paucity of research into the effect of radiation exposure in tandem with common environmental contaminants due to the inherent difficulties involved. In vitro cell cultures are particularly suited to the study of toxic mechanisms due to their proximity to toxic modes of action and the absence of the multiple defence mechanisms present in intact organisms. Primary cell cultures are particularly beneficial in this area of research as they still maintain many of their tissue specific functions. The objective of this study was to distinguish different mechanisms of cell death (growth arrest, apoptosis, primary and secondary necrosis and proliferation), following combination exposure to ionising radiation and a heavy metal (ZnCl2). The model system employed was a primary cell culture of rainbow trout (Oncorhynchus mykiss) epidermal tissue which has been previously used to study the effects of various environmental agents in this laboratory. Apoptosis and necrosis were quantified morphologically while proliferation was assessed immuno-cyto-chemically using an anti PCNA (proliferating cell nuclear antigen) antibody. While radiation doses up to and including 10 Gy had no effect on growth, exposure to ZnCl2 produced a significant dose dependent reduction in growth (10, 50, 75, 100 and 200 ppm ZnCl2). Preliminary results indicate no significant effect on growth following a combined exposure of 5 Gy + 50 ppm ZnCl2. These results may have important implications for understanding the mechanisms underlying cellular responses to multiple contaminant exposures. (author)

2004-09-06

328

Seasonal variations in the pattern of RNA metabolism of tuber tissue in response to excision and culture  

International Nuclear Information System (INIS)

Between December 1975 and June 1976 explants excised from Jerusalem artichoke tubers were cultured in the presence and in the absence of 2,4-D, the cells in the tissue dividing only in the presence of 2,4-D, in which the length of the first cell cycle increased nonlinearly from 18 hours to 40 hours as the tubers aged in storage at 4 0C. Simultaneously the amount of RNA in the tissue declined linearly from 8 to 5 ?g RNA per explant. Detailed examination of the RNA metabolism in dividing and in non-dividing cells during February and June 1976 revealed superimposed but independent responses to wounding during excision and to stimulation into growth by 2,4-D. The responses to wounding involved only a very low level of metabolic activity, were complete within a few hours of excision and changed very little with the storage of the tubers. Tissue treated with 2,4-D showed a much higher level of metabolic activity including the periodic accumulation of RNA coupled to its discontinuous synthesis. The features of these growth-related responses changed considerably during the investigation. (author)

1979-01-01

329

BAP, 2,4-D e ácido acetilsalicílico na indução e diferenciação de calos em anteras de Coffea arabica L BAP, 2,4-D and acetyl-salicylic acid on the callus induction and differentiation in Coffea arabica L. anthers  

Directory of Open Access Journals (Sweden)

Full Text Available O melhoramento genético do cafeeiro por meio de métodos convencionais é um processo demorado para se obter uma nova cultivar. A redução desse tempo é possível através da produção de linhagens homozigóticas, oriundas de dihaplóides obtidas através da cultura de anteras. Objetivou-se aplicar a técnica da cultura de anteras em diferentes cvs. de Coffea arabica L. para induzir a formação de calos e regenerar plântulas di-haplóides, com uso de reguladores vegetais. Os experimentos foram conduzidos no laboratório de Biotecnologia Vegetal da Universidade Federal de Uberlândia (UFU. Anteras das cultivares Mundo Novo LCP-379-19 e Catuaí Vermelho H2077-2-5-44 foram inoculadas em meio MS suplementado com 2,0 mg L-1 de 2,4-D e AAS, nas concentrações de 0; 8; 16; 32 e 64 mg L-1. Calos de 'Catuaí Vermelho 44' foram subcultivados em meio MS acrescido de diferentes concentrações de BAP (0; 2; 4 e 8 mg L-1 e 2,4-D (0; 1; 2 e 4 mg L-1. Tanto para as cvs. Mundo Novo quanto para Catuaí Vermelho 44 o aumento das concentrações de AAS diminuiu a formação de próembrióides nos calos e somente o 2,4-D foi capaz de promover a formação de calos friáveis, porém o equilíbrio da auxina e da citocinina utilizadas no trabalho, favoreceram a produção de calos friáveis.Coffee plant breeding through conventional methods demands a long time to obtain new cultivars. The reduction of this period is possible through the production of homozygous lines, from dihaploids obtained via anther culture. The aim of this study was to apply the anther culture technique on different C. arabica L. cultivars to induce calli formation and to regenerate dihaploid seedlings with the use of plant growth regulators. The experiments were accomplished in the Plant Biotechnology laboratory at Uberlândia Federal University (UFU. Anthers of the cultivars Mundo Novo LCP-379-19 and Catuaí Vermelho H2077-2-5-44 were inoculated on MS medium supplemented with 2.0 mg L-1 2,4-D and ASA at 0, 8, 16, 32 or 64 mg L-1. 'Catuaí Vermelho 44' calli were subcultured on MS supplemented with different concentrations of BAP (0, 2, 4 or 8 mg L-1 and 2,4-D (0, 1, 2 or 4 mg L-1. The increase in ASA concentrations decreased the pro-embryoid formation on calli of both cultivars and only 2,4-D promoted the formation of friable calli. However, the balance of auxin and cytokinin used in this study favored the production of friable calli.

Adelaide Siqueira Silva

2009-10-01

330

Differences in population structure of the anther smut fungus Microbotryum violaceum on two closely related host species, Silene latifolia and S. dioica.  

Science.gov (United States)

We investigated the genetic population structure of the sexually transmitted plant pathogen, the fungus Microbotryum violaceum, on the two closely related host species Silene latifolia and S. dioica using microsatellite markers. We found strong deviations from Hardy-Weinberg expectations, with significant heterozygote deficiency in almost all populations. Fungal strains from the two host species were differentiated, and these host races differed in amount of variation within populations and differentiation among populations. Anther smut from S. latifolia harboured significantly less microsatellite diversity and were more genetically differentiated from each other than those from S. dioica. Small effective population sizes, rapid population turnover, and less gene flow among populations could lead to this higher population differentiation and lower within population genetic diversity for anther smut populations on S. latifolia than on S. dioica. These results are in concordance with host ecology because S. latifolia grows in more disturbed habitats than S. dioica and may provide a shorter-lived host environment. PMID:11298945

Bucheli, E; Gautschi, B; Shykoff, J A

2001-02-01

331

``Yo soy indígena'': identifying and using traditional ecological knowledge (TEK) to make the teaching of science culturally responsive for Maya girls  

Science.gov (United States)

This study examines how traditional ecological knowledge—TEK—can be identified and utilized to create culturally responsive science learning opportunities for Maya girls from a community in the Guatemalan highlands. Maya girls are situated in a complex socio-historical and political context rooted in racism and sexism. This study contextualizes the current situation of Maya women and girls in Guatemala and emphasizes the important need for educators to create science-learning opportunities that are culturally congruent. The author posits that when considering how to make the teaching and learning of science culturally responsive for Maya girls, educators must begin with the scientific knowledge inherent within Maya communities. Indigenous communities have a wealth of TEK that can be used to contextualize science curricula that can be purposely designed to meet the nuanced cultural needs of traditional Maya girls within and outside Guatemala.

Hamlin, Maria L.

2013-12-01

332

Response surface optimisation for acetone-butanol-ethanol production from cassava starch by co-culture of Clostridium butylicum and Bacillus subtilis  

Directory of Open Access Journals (Sweden)

Full Text Available Acetone-butanol-ethanol (ABE production from cassava starch was enhanced by a syntrophic co-culture of Clostridium butylicum TISTR 1032 and high amylase producing Bacillus subtilis WD 161 without anaerobic pretreatment. The production of amylase and ABE using this co-culture were respectively 16 and 6 times higher than those using the pure culture of C. butylicum TISTR 1032. The effect of the medium components on the performance of the co-culture was investigated using response surface methodology (RSM. Among the investigated components, cassava starch and ammonium nitrate contributed a significant effect on the production of amylase and ABE, while yeast extract had less effect. Based on the optimum strategy using RSM, the ABE production by the co-culture was improved 2.2-fold compared with that obtained from the initial condition and with a minimum requirement of nitrogen source.

Benjamas Cheirsilp

2011-11-01

333

Mutation in continuous cultures of Schizosaccharomyces pombe II. Effect of amino acid starvation on mutational response and DNA concentration.  

Science.gov (United States)

In agreement with the results obtained in Escherichia coli by other workers and our own previous data, the kinetics with which spontaneous mutations to resistance to the 12,13-epoxytrichothecene trichodermin accumulate in a lysine auxotroph of Schizosaccharomyces pombe are dependent upon the nutrilite used to limit the growth of the population. Under conditions of glucose-limitation mutation accumulation is proportional to generation time, while under lysine-limitation it becomes proportional to chronological time. In contrast to observations made in bacterial system, however, no significant change in the DNA content per cell is noted in slow growing cultures grown under amino acid starvation. These findings help to eliminate some of the theories put forward to explain the differential mutational responses observed under different growth limiting regimes. PMID:651937

McAthey, P; Kilbey, B

1978-05-01

334

Dynamics of the transcriptome response of cultured human embryonic stem cells to ionizing radiation exposure.  

Science.gov (United States)

One of the key consequences of exposure of human cells to genotoxic agents is the activation of DNA damage responses (DDR). While the mechanisms underpinning DDR in fully differentiated somatic human cells have been studied extensively, molecular signaling events and pathways involved in DDR in pluripotent human embryonic stem cells (hESC) remain largely unexplored. We studied changes in the human genome-wide transcriptome of H9 hESC line following exposures to 1Gy of gamma-radiation at 2h and 16h post-irradiation. Quantitative real-time PCR was performed to verify the expression data for a subset of genes. In parallel, the cell growth, DDR kinetics, and expression of pluripotency markers in irradiated hESC were monitored. The changes in gene expression in hESC after exposure to ionizing radiation (IR) are substantially different from those observed in somatic human cell lines. Gene expression patterns at 2h post-IR showed almost an exclusively p53-dependent, predominantly pro-apoptotic, signature with a total of only 30 up-regulated genes. In contrast, the gene expression patterns at 16h post-IR showed 354 differentially expressed genes, mostly involved in pro-survival pathways, such as increased expression of metallothioneins, ubiquitin cycle, and general metabolism signaling. Cell growth data paralleled trends in gene expression changes. DDR in hESC followed the kinetics reported for human somatic differentiated cells. The expression of pluripotency markers characteristic of undifferentiated hESC was not affected by exposure to IR during the time course of our analysis. Our data on dynamics of transcriptome response of irradiated hESCs may provide a valuable tool to screen for markers of IR exposure of human cells in their most naive state; thus unmasking the key elements of DDR; at the same time, avoiding the complexity of interpreting distinct cell type-dependent genotoxic stress responses of terminally differentiated cells. PMID:21376742

Sokolov, Mykyta V; Panyutin, Irina V; Panyutin, Igor G; Neumann, Ronald D

2011-05-10

335

Dynamics of the transcriptome response of cultured human embryonic stem cells to ionizing radiation exposure  

Energy Technology Data Exchange (ETDEWEB)

One of the key consequences of exposure of human cells to genotoxic agents is the activation of DNA damage responses (DDR). While the mechanisms underpinning DDR in fully differentiated somatic human cells have been studied extensively, molecular signaling events and pathways involved in DDR in pluripotent human embryonic stem cells (hESC) remain largely unexplored. We studied changes in the human genome-wide transcriptome of H9 hESC line following exposures to 1 Gy of gamma-radiation at 2 h and 16 h post-irradiation. Quantitative real-time PCR was performed to verify the expression data for a subset of genes. In parallel, the cell growth, DDR kinetics, and expression of pluripotency markers in irradiated hESC were monitored. The changes in gene expression in hESC after exposure to ionizing radiation (IR) are substantially different from those observed in somatic human cell lines. Gene expression patterns at 2 h post-IR showed almost an exclusively p53-dependent, predominantly pro-apoptotic, signature with a total of only 30 up-regulated genes. In contrast, the gene expression patterns at 16 h post-IR showed 354 differentially expressed genes, mostly involved in pro-survival pathways, such as increased expression of metallothioneins, ubiquitin cycle, and general metabolism signaling. Cell growth data paralleled trends in gene expression changes. DDR in hESC followed the kinetics reported for human somatic differentiated cells. The expression of pluripotency markers characteristic of undifferentiated hESC was not affected by exposure to IR during the time course of our analysis. Our data on dynamics of transcriptome response of irradiated hESCs may provide a valuable tool to screen for markers of IR exposure of human cells in their most naive state; thus unmasking the key elements of DDR; at the same time, avoiding the complexity of interpreting distinct cell type-dependent genotoxic stress responses of terminally differentiated cells.

Sokolov, Mykyta V., E-mail: sokolovm@mail.nih.gov [Nuclear Medicine Division, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 (United States); Panyutin, Irina V., E-mail: ipanyutinv@mail.nih.gov [Nuclear Medicine Division, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 (United States); Panyutin, Igor G., E-mail: igorp@helix.nih.gov [Nuclear Medicine Division, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 (United States); Neumann, Ronald D., E-mail: rneumann@mail.nih.gov [Nuclear Medicine Division, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 (United States)

2011-05-10

336

Thermally responsive polymeric hydrogel brushes: synthesis, physical properties and use for the culture of chondrocytes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Hydrogel brushes are materials composed of a water-swollen network, which contains polymer chains that are grafted with another polymer. Using a thermally responsive polymer, poly(N-isopropyl acrylamide) (polyNIPAM), as the graft component we are able to maintain the critical solution temperature (Tcrit), independent of the overall composition of the material, at approximately 32°C. The change in swelling at Tcrit is a function of the amount of polyNIPAM in the system. However, there is a mu...

Collett, John; Crawford, Aileen; Hatton, Paul V.; Geoghegan, Mark; Rimmer, Stephen

2007-01-01

337

Quantification of Dynamic Morphological Drug Responses in 3D Organotypic Cell Cultures by Automated Image Analysis.  

Science.gov (United States)

Glandular epithelial cells differentiate into complex multicellular or acinar structures, when embedded in three-dimensional (3D) extracellular matrix. The spectrum of different multicellular morphologies formed in 3D is a sensitive indicator for the differentiation potential of normal, non-transformed cells compared to different stages of malignant progression. In addition, single cells or cell aggregates may actively invade the matrix, utilizing epithelial, mesenchymal or mixed modes of motility. Dynamic phenotypic changes involved in 3D tumor cell invasion are sensitive to specific small-molecule inhibitors that target the actin cytoskeleton. We have used a panel of inhibitors to demonstrate the power of automated image analysis as a phenotypic or morphometric readout in cell-based assays. We introduce a streamlined stand-alone software solution that supports large-scale high-content screens, based on complex and organotypic cultures. AMIDA (Automated Morphometric Image Data Analysis) allows quantitative measurements of large numbers of images and structures, with a multitude of different spheroid shapes, sizes, and textures. AMIDA supports an automated workflow, and can be combined with quality control and statistical tools for data interpretation and visualization. We have used a representative panel of 12 prostate and breast cancer lines that display a broad spectrum of different spheroid morphologies and modes of invasion, challenged by a library of 19 direct or indirect modulators of the actin cytoskeleton which induce systematic changes in spheroid morphology and differentiation versus invasion. These results were independently validated by 2D proliferation, apoptosis and cell motility assays. We identified three drugs that primarily attenuated the invasion and formation of invasive processes in 3D, without affecting proliferation or apoptosis. Two of these compounds block Rac signalling, one affects cellular cAMP/cGMP accumulation. Our approach supports the growing needs for user-friendly, straightforward solutions that facilitate large-scale, cell-based 3D assays in basic research, drug discovery, and target validation. PMID:24810913

Härmä, Ville; Schukov, Hannu-Pekka; Happonen, Antti; Ahonen, Ilmari; Virtanen, Johannes; Siitari, Harri; Akerfelt, Malin; Lötjönen, Jyrki; Nees, Matthias

2014-01-01

338

Quantification of Dynamic Morphological Drug Responses in 3D Organotypic Cell Cultures by Automated Image Analysis  

Science.gov (United States)

Glandular epithelial cells differentiate into complex multicellular or acinar structures, when embedded in three-dimensional (3D) extracellular matrix. The spectrum of different multicellular morphologies formed in 3D is a sensitive indicator for the differentiation potential of normal, non-transformed cells compared to different stages of malignant progression. In addition, single cells or cell aggregates may actively invade the matrix, utilizing epithelial, mesenchymal or mixed modes of motility. Dynamic phenotypic changes involved in 3D tumor cell invasion are sensitive to specific small-molecule inhibitors that target the actin cytoskeleton. We have used a panel of inhibitors to demonstrate the power of automated image analysis as a phenotypic or morphometric readout in cell-based assays. We introduce a streamlined stand-alone software solution that supports large-scale high-content screens, based on complex and organotypic cultures. AMIDA (Automated Morphometric Image Data Analysis) allows quantitative measurements of large numbers of images and structures, with a multitude of different spheroid shapes, sizes, and textures. AMIDA supports an automated workflow, and can be combined with quality control and statistical tools for data interpretation and visualization. We have used a representative panel of 12 prostate and breast cancer lines that display a broad spectrum of different spheroid morphologies and modes of invasion, challenged by a library of 19 direct or indirect modulators of the actin cytoskeleton which induce systematic changes in spheroid morphology and differentiation versus invasion. These results were independently validated by 2D proliferation, apoptosis and cell motility assays. We identified three drugs that primarily attenuated the invasion and formation of invasive processes in 3D, without affecting proliferation or apoptosis. Two of these compounds block Rac signalling, one affects cellular cAMP/cGMP accumulation. Our approach supports the growing needs for user-friendly, straightforward solutions that facilitate large-scale, cell-based 3D assays in basic research, drug discovery, and target validation.

Harma, Ville; Schukov, Hannu-Pekka; Happonen, Antti; Ahonen, Ilmari; Virtanen, Johannes; Siitari, Harri; Akerfelt, Malin; Lotjonen, Jyrki; Nees, Matthias

2014-01-01

339

Cophylogeny of the anther smut fungi and their caryophyllaceous hosts: Prevalence of host shifts and importance of delimiting parasite species for inferring cospeciation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: Using phylogenetic approaches, the expectation that parallel cladogenesis should occur between parasites and hosts has been validated in some studies, but most others provided evidence for frequent host shifts. Here we examine the evolutionary history of the association between Microbotryum fungi that cause anther smut disease and their Caryophyllaceous hosts. We investigated the congruence between host and parasite phylogenies, inferred cospeciation events and host shifts, and as...

Refregier, Guislaine; Le Gac, Mickael; Jabbour, Florian; Widmer, Alex; Shykoff, Jacqui A.; Yockteng, Roxana; Hood, Michael E.; Giraud, Tatiana

2008-01-01

340

Anther and pollen development in some species of Poaceae (Poales) Desenvolvimento da antera e do grão de pólen em espécies de Poaceae (Poales)  

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Anther and pollen development were studied in Olyra humilis Nees, Sucrea monophylla Soderstr, (Bambusoideae), Axonopus aureus P. Beauv., Paspalum polyphyllum Nees ex Trin. (Panicoideae), Eragrostis solida Nees, and Chloris elata Desv. (Chloridoideae). The objective of this study was to characterise, embryologically, these species of subfamilies which are considered basal, intermediate and derivate, respectively. The species are similar to each other and to other Poaceae. They present the foll...

At, Nakamura; Hm, Longhi-wagner; Vl, Scatena

2010-01-01

 
 
 
 
341

Studies of the in vitro selection of novel disease resistant plants and mutagenesis of cultured cells  

International Nuclear Information System (INIS)

Plants of Brassica napus ssp. oleifera cv Primor which had been regenerated from secondary embryoids were found to be more susceptible to Leptosphaeria maculans than those grown from seed, but were generally more resistant to Alternaria brassicicola. In vitro selection of secondary embryoids on medium containing toxic filtrates of A. brassicicola did not result in significantly higher levels of resistance to the pathogen, and in the case of L. maculans, the plants were found to be more susceptible after the selection steps. When tissues were challenged with pycnidiospores of L. maculans it was possible to define growth conditions in which differential reactions correlated with in vivo responses. Studies on in vitro mutagenesis revealed that low doses of gamma rays enhanced the production of anther embryoids, although, whereas both gamma and X-rays reduced the regeneration capacity of treated tissues, irradiation with UV did not. Increased resistance to A. brassicicola was detected in doubled haploid plants following a seed treatment with EMS and from microspore culture following UV irradiation. In vitro studies of Helianthus annuus and Macrophomina phaseolina, and Zea mays and Fusarium moniliforme are also reported. (author). 28 refs, 2 figs, 2 tabs

1993-12-01

342

Ultrastructural analysis of the behavior of the dimorphic fungus Microbotryum violaceum in fungus-induced anthers of female Silene latifolia flowers.  

Science.gov (United States)

The development of male organs is induced in female flowers of the dioecious plant Silene latifolia by infection with the fungus Microbotryum violaceum. Stamens in a healthy female flower grow only to stage 6, whereas those in an infected female flower develop to the mature stage (stage 12), at which the stamens are filled with fungal teliospores instead of pollen grains. To investigate these host-parasite interactions, young floral buds and fungus-induced anthers of infected female flowers were examined by electron microscopy following fixation by a high-pressure freezing method. Using this approach, we found that parasitic hyphae of this fungus contain several extracellular vesicles and have a consistent appearance up to stage 8. At that stage, parasitic hyphae are observed adjacent to dying sporogenous cells in the infected female anther. At stage 9, an increased number of dead and dying sporogenous cells is observed, among which the sporogenous hyphae of the fungus develop and form initial teliospores. Several types of electron-dense material are present in proximity to some fungi at this stage. The initial teliospores contain two types of vacuoles, and the fungus cell wall contains abundant carbohydrate, as revealed by silver protein staining. The sporogenous cell is probably sensitive to infection by the fungus, resulting in disruption. In addition, the fungus accelerates cell death in the anther and utilizes constituents of the dead host cell to form the mature teliospore. PMID:16333578

Uchida, Wakana; Matsunaga, Sachihiro; Kawano, Shigeyuki

2005-12-01

343

Particles from wood smoke and traffic induce differential pro-inflammatory response patterns in co-cultures  

International Nuclear Information System (INIS)

The inflammatory potential of particles from wood smoke and traffic has not been well elucidated. In this study, a contact co-culture of monocytes and pneumocytes was exposed to 10-40 ?g/cm2 of particles from wood smoke and traffic for 12, 40 and 64 h to determine their influence on pro-inflammatory cytokine release (TNF-?, IL-1, IL-6, IL-8) and viability. To investigate the role of organic constituents in cytokine release the response to particles, their organic extracts and the washed particles were compared. Antagonists were used to investigate source-dependent differences in intercellular signalling (TNF-?, IL-1). The cytotoxicity was low after exposure to particles from both sources. However, wood smoke, and to a lesser degree traffic-derived particles, induced a reduction in cell number, which was associated with the organic fraction. The release of pro-inflammatory cytokines was similar for both sources after 12 h, but traffic induced a greater release than wood smoke particles with increasing exposure time. The organic fraction accounted for the majority of the cytokine release induced by wood smoke, whereas the washed traffic particles induced a stronger response than the corresponding organic extract. TNF-? and IL-1 antagonists reduced the release of IL-8 induced by particles from both sources. In contrast, the IL-6 release was only reduced by the IL-1 antagonist during exposure to traffic-derived particles. In summary, particles from wood smoke and traffic induced differential pro-inflammatory response patterns with respect to cytokine release and cell number. Moreover, the influence of the organic particle fraction and intercellular signalling on the pro-inflammatory response seemed to be source-dependent

2008-10-15

344

Statistical optimization of culture conditions by response surface methodology for synthesis of lipase with Enterobacter aerogenes  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Optimization of lipase production by Enterobacter aerogenes was carried out using response surface methodology (RSM) where the statistical model was obtained by fractional factorial central composite design. The influence of various physico-chemical parameters, viz. temperature, oil concentration, i [...] noculum volume, pH and incubation period on lipase production was examined. Optimization of physico-chemical parameters resulted 1.4- fold increase in lipase activity. The optimum levels of parameters were 34°C, oil concentration 3%, inoculum volume 7%, pH 7 and incubation time 60 h for obtaining a maximum lipase activity of 27.25 U/ml.

Annapurna, Kumari; Paramita, Mahapatra; Rintu, Banerjee.

345

Arsenite and monomethylarsonous acid generate oxidative stress response in human bladder cell culture  

International Nuclear Information System (INIS)

Arsenicals have commonly been seen to induce reactive oxygen species (ROS) which can lead to DNA damage and oxidative stress. At low levels, arsenicals still induce the formation of ROS, leading to DNA damage and protein alterations. UROtsa cells, an immortalized human urothelial cell line, were used to study the effects of arsenicals on the human bladder, a site of arsenical bioconcentration and carcinogenesis. Biotransformation of As(III) by UROtsa cells has been shown to produce methylated species, namely monomethylarsonous acid [MMA(III)], which has been shown to be 20 times more cytotoxic. Confocal fluorescence images of UROtsa cells treated with arsenicals and the ROS sensing probe, DCFDA, showed an increase of intracellular ROS within five min after 1 ?M and 10 ?M As(III) treatments. In contrast, 50 and 500 nM MMA(III) required pretreatment for 30 min before inducing ROS. The increase in ROS was ameliorated by preincubation with either SOD or catalase. An interesting aspect of these ROS detection studies is the noticeable difference between concentrations of As(III) and MMA(III) used, further supporting the increased cytotoxicity of MMA(III), as well as the increased amount of time required for MMA(III) to cause oxidative stress. These arsenical-induced ROS produced oxidative DNA damage as evidenced by an increase in 8-hydroxyl-2'-deoxyguanosine (8-oxo-dG) with either 50 nM or 5 ?M MMA(III) exposure. These findings provide support that MMA(III) cause a genotoxic response upon generation of ROS. Both As(III) and MMA(III) were also able to induce Hsp70 and MT protein levels above control, showing that the cells recognize the ROS and respond. As(III) rapidly induces the formation of ROS, possibly through it oxidation to As(V) and further metabolism to MMA(III)/(V). These studies provide evidence for a different mechanism of MMA(III) toxicity, one that MMA(III) first interacts with cellular components before an ROS response is generated, taking longer to produce the effect, but with more substantial harm to the cell

2006-11-15

346

Recombinant ovine and bovine interferons tau regulate prostaglandin production and oxytocin response in cultured bovine endometrial cells.  

Science.gov (United States)

At the time of recognition of pregnancy, the bovine conceptus (embryo and associated membranes) must produce a signal that will prevent luteolysis otherwise induced by pulsatile release of prostaglandin (PG) F2alpha from the uterus in response to oxytocin (OT). In ruminants, trophoblastic interferon tau (IFN-tau) released by the conceptus appears to be the most likely candidate to trigger the establishment of pregnancy. We have compared the effect of recombinant (r) ovine (o) and bovine (b) IFN-tau on PG production, using a fully characterized model of cultured endometrial cells. In uterine epithelial cells, the production of PGF2alpha was stimulated 7.1-fold (p regulation of PG production. In uterine stromal cells, roIFN-tau and rbIFN-tau stimulated PGE2 and PGF2alpha production 12-fold (p regulates PGs by stimulating PGE2 preferentially, and 3) rIFN-tau transforms the response to OT from stimulation of PGF2alpha to stimulation of PGE2. PMID:9116139

Asselin, E; Bazer, F W; Fortier, M A

1997-02-01

347

Inflammatory cytokine and microRNA responses of primary human dendritic cells cultured with Helicobacter pylori strains.  

Directory of Open Access Journals (Sweden)

Full Text Available Primary human dendritic cells (DC were used to explore the inflammatory effectors, including cytokines and microRNAs, regulated by Helicobacter pylori. In a 48 h ex-vivo co-culture system, both H. pylori B38 and B45 strains activated human DCs and promoted a strong inflammatory response characterized by the early production of pro-inflammatory TNF? and IL-6 cytokines, followed by IL-10, IL-1ß and IL-23 secretion. IL-23 was the only cytokine dependent on the cag pathogenicity island status of the bacterial strains. DC activation and cytokine production were accompanied by an early miR-146a upregulation followed by a strong miR-155 induction, which mainly controlled TNF? production. These results pave the way for further investigations into the nature of H. pylori antigens and the subsequently activated signaling pathways involved in the inflammatory response to H. pylori infection, the deregulation of which may likely contribute to gastric lymphomagenesis.

PHILIPPELEHOURS

2013-08-01

348

Growth and genetic responses of Salmonella Typhimurium to pH-shifts in an anaerobic continuous culture.  

Science.gov (United States)

Salmonella infection of chickens that leads to potential human foodborne salmonellosis continues to be a concern. Changes in the pH of poultry gastrointestinal tract could influence Salmonella growth and virulence response. In the current study, growth responses of a chicken isolate Salmonella enterica serovar Typhimurium (ST) to three incremental pH-shifts (6.17-7.35) in continuous cultures (CC) were evaluated. The expression of rpoS and hilA was determined by real time-polymerase chain reaction (RT-PCR) as well. Increases in pH resulted in higher cell protein concentrations, glucose disappearance, and glucose and ATP yields. Although with some inconsistency between the two trials, the data indicated that the ammonia release into media was favored by low pH. The pH shifts did not significantly affect acetate biosynthesis. No consistent trends of pH influence on propionate and butyrate production could be detected. In all three pH shifts, relative expression of hilA was dominant at 0h which represented CC steady state. In pH shift 7.35-6.86 (Trial 1), the relative expression of rpoS at time 0 and 1h were over five-fold higher than after 3 and 6h of growth. Overall, the results suggest that ST physiology is altered by changes in pH, which could be determinant factors for ST survival in the poultry gastrointestinal ecosystems. PMID:18061487

Dunkley, K D; Callaway, T R; Chalova, V I; Anderson, R C; Kundinger, M M; Dunkley, C S; Nisbet, D J; Ricke, S C

2008-02-01

349

Eosinophils altered phenotypically and primed by culture with granulocyte/macrophage colony-stimulating factor and 3T3 fibroblasts generate leukotriene C4 in response to FMLP.  

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Normodense eosinophils failed to generate leukotriene C4 (LTC4) in response to incremental concentrations of FMLP but did produce LTC4 when stimulated with calcium ionophore A23187. Normodense eosinophils, maintained in culture with 10(-11) M granulocyte/macrophage colony-stimulating factor (GM-CSF) in the presence of 3T3 fibroblasts, became responsive to transmembrane stimulation with FMLP by day 4 with a maximal effect by day 7. After 7 d of culture, hypodense eosinophils stimulated with 2 ...

1991-01-01

350

Global transcriptome analysis of two ameiotic1 alleles in maize anthers: defining steps in meiotic entry and progression through prophase I  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Developmental cues to start meiosis occur late in plants. Ameiotic1 (Am1 encodes a plant-specific nuclear protein (AM1 required for meiotic entry and progression through early prophase I. Pollen mother cells (PMCs remain mitotic in most am1 mutants including am1-489, while am1-praI permits meiotic entry but PMCs arrest at the leptotene/zygotene (L/Z transition, defining the roles of AM1 protein in two distinct steps of meiosis. To gain more insights into the roles of AM1 in the transcriptional pre-meiotic and meiotic programs, we report here an in depth analysis of gene expression alterations in carefully staged anthers at 1 mm (meiotic entry and 1.5 mm (L/Z caused by each of these am1 alleles. Results 1.0 mm and 1.5 mm anthers of am1-489 and am1-praI were profiled in comparison to fertile siblings on Agilent® 4 × 44 K microarrays. Both am1-489 and am1-praI anthers are cytologically normal at 1.0 mm and show moderate transcriptome alterations. At the 1.5-mm stage both mutants are aberrant cytologically, and show more drastic transcriptome changes. There are substantially more absolute On/Off and twice as many differentially expressed genes (sterile versus fertile in am1-489 than in am1-praI. At 1.5 mm a total of 4,418 genes are up- or down-regulated in either am1-489 or am1-praI anthers. These are predominantly stage-specific transcripts. Many putative meiosis-related genes were found among them including a small subset of allele-specific, mis-regulated genes specific to the PMCs. Nearly 60% of transcriptome changes in the set of transcripts mis-regulated in both mutants (N = 530 are enriched in PMCs, and only 1% are enriched in the tapetal cell transcriptome. All array data reported herein will be deposited and accessible at MaizeGDB http://www.maizegdb.org/. Conclusions Our analysis of anther transcriptome modulations by two distinct am1 alleles, am1-489 and am1-praI, redefines the role of AM1 as a modulator of expression of a subset of meiotic genes, important for meiotic progression and provided stage-specific insights into the genetic networks associated with meiotic entry and early prophase I progression.

Fernandes John F

2011-08-01

351

Frequent biphasic cellular responses of permanent fish cell cultures to deoxynivalenol (DON)  

International Nuclear Information System (INIS)

Contamination of animal feed with mycotoxins is a major problem for fish feed mainly due to usage of contaminated ingredients for production and inappropriate storage of feed. The use of cereals for fish food production further increases the risk of a potential contamination. Potential contaminants include the mycotoxin deoxynivalenol (DON) which is synthesized by globally distributed fungi of the genus Fusarium. The toxicity of DON is well recognized in mammals. In this study, we confirm cytotoxic effects of DON in established permanent fish cell lines. We demonstrate that DON is capable of influencing the metabolic activity and cell viability in fish cells as determined by different assays to indicate possible cellular targets of this toxin. Evaluation of cell viability by measurement of membrane integrity, mitochondrial activity and lysosomal function after 24 h of exposure of fish cell lines to DON at a concentration range of 0-3000 ng ml-1 shows a biphasic effect on cells although differences in sensitivity occur. The cell lines derived from rainbow trout are particularly sensitive to DON. The focus of this study lies, furthermore, on the effects of DON at different concentrations on production of reactive oxygen species (ROS) in the different fish cell lines. The results show that DON mainly reduces ROS production in all cell lines that were used. Thus, our comparative investigations reveal that the fish cell lines show distinct species-related endpoint sensitivities that also depend on the type of tissue from which the cells were derived and the severity of exposure. - Highlights: ? DON uptake by cells is not extensive. ? All fish cell lines are sensitive to DON. ? DON is most cytotoxic to rainbow trout cells. ? Biphasic cellular responses were frequently observed. ? Our results are similar to studies on mammalian cell lines.

2011-10-01

352

Biochemical and morphological responses to abiotc elicitor chitin in suspension-cultured sugarcane cells  

Directory of Open Access Journals (Sweden)

Full Text Available Cells of Saccharum officinarum submitted to hydrolyzated chitin for 1 to 8h produced phenolic compounds. These alterations were observed through cytochemical methods using Toluidine Blue and Phloroglucinol/HCl. After 4 h, besides cell wall change, there was a change in nuclear pattern of chitin treated cells. There was a 96% increase in nuclear area in 6 h chitin treated material, as observed by Feulgen reaction. The treated cells showed chromatin compacted regions and a degeneration process of nucleoli. In the outer areas of cell wall, there was a polysaccharide desagregation, confirming results obtained for different plants with the use of other elicitors. Peroxidase activity was maximal after 4 h and decreased progressively. PAL activity started to increase at 4 h of incubation. These results showed that chitin hydrolyzate stimulated a defense response in sugarcane cells.Células de Saccharum officinarum quando submetidas a quitina hidrolisada por 1 a 8h produziram material fenólico. Essas alterações foram observadas por meio de métodos citoquímicos como o Azul de Toluidina e Floroglucinol/HCl. Após 4 h, além das mudanças nas paredes celulares houve uma mudança no padrão nuclear das células tratadas com quitina. Por observação da reação de Feulgen, houve um aumento de 96% na área nuclear no material em 6h. Para as células tratadas foram observadas regiões de cromatina compactada e um processo de degeneração do nucléolo. Nas áreas externas da parede celular existia uma desagregação dos polisacarídios confirmando os resultados obtidos para diferentes plantas com o uso de outros elicitores. A atividade da peroxidase foi maxima após 4 h e então decresceu progressivamente. A atividade da PAL aumentou a partir de 4 h de incubação. Estes resultados mostram que o hidrolisado de quitina estimula as respostas de defesa em células de cana.

Maria Izabel Gallão

2010-04-01

353

Yield response of Bere, a Scottish barley landrace, to cultural practices and agricultural inputs  

Directory of Open Access Journals (Sweden)

Full Text Available There is very little documented about the response of cereal landraces to modern agricultural practices. Bere is a Scottish barley (Hordeum vulgare L. landrace which is grown in Orkney to supply meal for baking. A recent research programme has improved yields and the security of the Bere harvest, making it possible to supply a new market for grain to produce specialist whiskies. At the start of this research, a survey of Orkney farmers who had grown Bere since the 1980s showed that most had planted it at the traditional time in mid-May, used few inputs and considered the main constraints of the crop to be low yield (2.8 to 3.8 t/ha and susceptibility to lodging. Three years of trials in Orkney between 2003 and 2005 showed very significant increases in grain yield (17-76% and thousand grain weight from planting Bere earlier, in the second half of April. This also had the advantage of an earlier and more secure harvest. Yields showed smaller, but often significant, increases (5-11% from applying mineral fertiliser, growth regulator or fungicide, while combinations of growth regulator and fungicide increased yields from 10- 22%. In spite of usually increasing grain yield, growth regulator did not always control lodging. Although the use of inputs often increased the gross margins of growing Bere, a trial in 2005 showed that early planting was a more cost effective single intervention than either the use of fungicide or growth regulator. By increasing grower profits and reducing harvesting risks, these results have made it viable for more farmers to grow Bere in its region of origin, providing growers and end-users with additional income and contributing to the in situ conservation of this landrace.

John Wishart

2011-11-01

354

Evaluating virulence of waterborne and clinical Aeromonas isolates using gene expression and mortality in neonatal mice followed by assessing cell culture’s ability to predict virulence based on transcriptional response  

Energy Technology Data Exchange (ETDEWEB)

Aims: To assess the virulence of Aeromonas spp. using two models, a neonatal mouse assay and a mouse intestinal cell culture. Methods and Results: After artificial infection with a variety of Aeromonas spp., mRNA extracts from the two models were processed and hydridized to murine microarrays to determine host gene response. Definition of virulence was determined based on host mRNA production in murine neonatal intestinal tissue and mortality of infected animals. Infections of mouse intestinal cell cultures were then performed to determine whether this simpler model system’s mRNA responses correlated to neonatal results and therefore be predictive of virulence of Aeromonas spp. Virulent aeromonads up-regulated transcripts in both models including multiple host defense gene products (chemokines, regulation of transcription and apoptosis and cell signalling). Avirulent species exhibited little or no host response in neonates. Mortality results correlated well with both bacterial dose and average fold change of up-regulated transcripts in the neonatal mice. Conclusions: Cell culture results were less discriminating but showed promise as potentially being able to be predictive of virulence. Jun oncogene up-regulation in murine cell culture is potentially predictive of Aeromonas virulence. Significance and Impact of the Study: Having the ability to determine virulence of waterborne pathogens quickly would potentially assist public health officials to rapidly assess exposure risks.

Hayes, S L; Rodgers, M R; Lye, D J; Stelma, G N; McKinstry, Craig A.; Malard, Joel M.; Vesper, Sephen J.

2007-10-01

355

TamiR159 directed wheat TaGAMYB cleavage and its involvement in anther development and heat response.  

Science.gov (United States)

In Arabidopsis and rice, miR159-regulated GAMYB-like family transcription factors function in flower development and gibberellin (GA) signaling in cereal aleurone cells. In this study, the involvement of miR159 in the regulation of its putative target TaGAMYB and its relationship to wheat development were investigated. First, we demonstrated that cleavage of TaGAMYB1 and TaGAMYB2 was directed by miR159 using 5'-RACE and a transient expression system. Second, we overexpressed TamiR159, TaGAMYB1 and mTaGAMYB1 (impaired in the miR159 binding site) in transgenic rice, revealing that the accumulation in rice of mature miR159 derived from the precursor of wheat resulted in delayed heading time and male sterility. In addition, the number of tillers and primary branches in rice overexpressing mTaGAMYB1 increased relative to the wild type. Our previous study reported that TamiR159 was downregulated after two hours of heat stress treatment in wheat (Triticum aestivum L.). Most notably, the TamiR159 overexpression rice lines were more sensitive to heat stress relative to the wild type, indicating that the downregulation of TamiR159 in wheat after heat stress might participate in a heat stress-related signaling pathway, in turn contributing to heat stress tolerance. PMID:23133634

Wang, Yu; Sun, Fenglong; Cao, Hua; Peng, Huiru; Ni, Zhongfu; Sun, Qixin; Yao, Yingyin

2012-01-01

356

TamiR159 Directed Wheat TaGAMYB Cleavage and Its Involvement in Anther Development and Heat Response  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In Arabidopsis and rice, miR159-regulated GAMYB-like family transcription factors function in flower development and gibberellin (GA) signaling in cereal aleurone cells. In this study, the involvement of miR159 in the regulation of its putative target TaGAMYB and its relationship to wheat development were investigated. First, we demonstrated that cleavage of TaGAMYB1 and TaGAMYB2 was directed by miR159 using 5?-RACE and a transient expression system. Second, we overexpressed TamiR159, TaGAM...

Wang, Yu; Sun, Fenglong; Cao, Hua; Peng, Huiru; Ni, Zhongfu; Sun, Qixin; Yao, Yingyin

2012-01-01

357

Responses of primary cultured haemocytes from the marine gastropod Haliotis tuberculata under 10-day exposure to cadmium chloride  

Energy Technology Data Exchange (ETDEWEB)

Among metals, cadmium, a non-essential element, is an important pollutant that is released into aquatic environments. Due to its persistence and bioaccumulation, this metal has been shown to exert immunological effects on organisms. The objective of the present study was to investigate the in vitro effects of cadmium chloride using a haemocyte primary culture from the European abalone, Haliotis tuberculata. Most studies have maintained viable haemocytes in vitro for periods ranging from several hours to several days during acute exposures. Few investigations have reported the effects of metals using longer in vitro exposures, which are more realistic with regard to mimicking environmental conditions. In this study, we exposed abalone haemocytes to concentrations from 0.5 to 50,000 {mu}g L{sup -1} of CdCl{sub 2} for 10 days. The effects of cadmium chloride were reflected in a significant decrease in the number of viable cells and morphological modifications in a concentration-dependent manner beginning at a concentration of 500 {mu}g L{sup -1} as well as in some physiological processes, such as phagocytotic activity and the number of lysosome-positive cells. In contrast, phenoloxidase (PO) activity and reactive oxygen species (ROS) production were increased beginning at a concentration of 5 {mu}g L{sup -1}, which is consistent with environmental concentrations in polluted sites. For PO activity and ROS production, maximally 9-fold and 130% inductions, respectively, were recorded under the highest dose. These results thus indicate that cadmium chloride alters immune parameters of abalone haemocytes and that the long-term (10 days) primary culture system used here represents a suitable, sensitive in vitro model for assessing cytotoxic responses.

Latire, Thomas; Le Pabic, Charles; Mottin, Elmina; Mottier, Antoine; Costil, Katherine; Koueta, Noussithe; Lebel, Jean-Marc [UMR 100 IFREMER ' Physiologie et Ecophysiologie des Mollusques Marins' - IFR 146 ICORE - IBFA - Universite de Caen Basse-Normandie, Campus 1, Science C, Esplanade de la Paix, 14032 Caen cedex (France); Serpentini, Antoine, E-mail: antoine.serpentini@unicaen.fr [UMR 100 IFREMER ' Physiologie et Ecophysiologie des Mollusques Marins' - IFR 146 ICORE - IBFA - Universite de Caen Basse-Normandie, Campus 1, Science C, Esplanade de la Paix, 14032 Caen cedex (France)

2012-03-15

358

TrkB is responsible for EMT transition in malignant pleural effusions derived cultures from adenocarcinoma of the lung.  

Science.gov (United States)

Lung cancer is the leading cause of cancer-related mortality worldwide. Recent evidence indicates that tumors contain a subpopulation of cancer stem cells (CSCs) that are responsible for tumor maintenance and spread. CSCs have recently been linked to the occurrence of epithelial-to-mesenchymal transition (EMT). Neurotrophins (NTs) are growth factors that regulate the biology of embryonic stem cells and cancer cells, but still little is known about the role NTs in the progression of lung cancer. In this work, we investigated the role of the NTs and their receptors using as a study system primary cell cultures derived from malignant pleural effusions (MPEs) of patients with adenocarcinoma of the lung. We assessed the expression of NTs and their receptors in MPE-derived adherent cultures vs. spheroids enriched in CSC markers. We observed in spheroids a selectively enhanced expression of TrkB, both at the mRNA and protein levels. Both K252a, a known inhibitor of Trk activity, and a siRNA against TrkB strongly affected spheroid morphology, induced anoikis and decreased spheroid forming efficiency. Treatment with neurotrophins reversed the inhibitory effect of K252a. Importantly, TrkB inhibition caused loss of vimentin expression as well as that of a set of transcription factors known to be linked to EMT. These ex vivo results nicely correlated with an inverse relationship between TrkB and E-cadherin expression measured by immunohistochemistry in a panel of lung adenocarcinoma samples. We conclude that TrkB is involved in full acquisition of EMT in lung cancer, and that its inhibition results in a less aggressive phenotype. PMID:23656788

Ricci, Alberto; De Vitis, Claudia; Noto, Alessia; Fattore, Luigi; Mariotta, Salvatore; Cherubini, Emanuela; Roscilli, Giuseppe; Liguori, Giuseppina; Scognamiglio, Giosuè; Rocco, Gaetano; Botti, Gerardo; Giarnieri, Enrico; Giovagnoli, Maria Rosaria; De Toma, Giorgio; Ciliberto, Gennaro; Mancini, Rita

2013-06-01

359

Differential effect of culture epimastigotes and blood-form Trypamastigotes on normal mouse splenocyte responsiveness to mitogens  

Directory of Open Access Journals (Sweden)

Full Text Available Blood form trypomastigotes of the Y strain of T. cruzi, produced a strong inhibition of the blastogenic response to T and B cell mitogens, of the C3H/He, C57BLand BALB/cJ strains of mice, while culture epimastigotes of the Y strain kept in a medium that allows parasite growth at 26°. 30° and 37°C produced a strong stimulatory effect that was even higher than the effect of the mitogens alone. Both the inhibitory or the stimulatory effects were dose-dependent. The stimulatory effect of epimastigotes was also temperature-dependent producing increasedstimulation indexes as the temperature of parasite cultures was raised. Metabolically active,living parasites seemed to be necessary for an improved lymphocyte stimulation suggesting a potential role of secreted metabolites as polyclonal activators of mouse lymphocytes.Tripomastigotas de sangue da cepa Y de T. cruzi mostraram uma forte inibição da resposta de transformação blástica a mitógenos de células T e B, nas estirpes C3H/He, C57BL/6 e BALB/cJ de camundongos, enquanto epimastigotas de cultura da cepa Y mantidos em meio que permite o crescimento dos parasitas a 26-, 30-, 34- e 37-C mostraram um forte efeito estimulante, que foi inclusive maior que o efeito dos mitógenos isolados. Os efeitos de inibição e de estimulação foram dependentes da dose. O efeito estimulante dos epimastigotas também foi dependente da temperatura, encontrando-se maiores índices de estimulação à medida que a temperatura da cultura dos parasitas foi aumentada. Parasitas vivos, metabolicamente ativos, parecem ser necessários para a obtenção de uma maior estimulação dos linfócitos, o que sugere um papel potencial dos metabólitos segregados como ativadores policlonais dos linfócitos dos camundongos.

L. E. Serrano

1986-06-01

360

Automatically you become a polygamist': 'culture' and 'norms' as resources for normalization and managing accountability in talk about responses to infertility.  

Science.gov (United States)

In the developing world, infertility is a serious problem. It leads to both psychological and social hardship, in part because childless marriages often result in divorce, men taking another wife or extramarital relationships. Such responses have been attributed to cultural norms that mandate procreation. However, there are theoretical, methodological and moral issues with treating cultural norms as behavioural determinants. They have been insufficiently acknowledged in health research. Therefore, I demonstrate an alternative discursive approach, which examines how people actively mobilize ;culture' or ;norms' in interactions, and the interpersonal functions thereby fulfilled (e.g. blaming or justifying). Analysis is presented of interviews on (responses to) infertility in Malawi. I show how respondents construct polygamy and extramarital affairs as culturally and normatively required, ;automatic' and normal solutions for fertility problems and play down people's accountability for these practices. These accounts and constructions appear to facilitate engagement in affairs and polygamy when people face fertility problems, which seems problematic from a health and gender perspective. Thus, detailed analysis of how people use ;culture' and ;norms' in situ is important because it provides insights into its potentially undesirable consequences. Moreover, such analysis provides a starting point for culturally and gender sensitive interventions, since it highlights people's agency, and creates a space to re-construct and change practices. PMID:19228828

de Kok, B C

2009-03-01

 
 
 
 
361

Ultrastructural studies on the sporogenous tissue and anther wall of Leucojum aestivum (amaryllidaceae) in different developmental stages  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Neste estudo, ultraestruturas da parede da antera e tecido esporogênico de Leucojum aestivumforam foram investigados durante diferentes estágios do desenvolvimento. Canais citomíticos foram vistos entre células - mãe de pólen durante a prófase I. Distribuição polar foi descrita no conteúdo da organe [...] la de células - mãe de pólen e em micrósporos nas fases iniciais da microesporogênese e também na mitose do pólen. Secreção ativa foi observada nas células tapetais. Registros prévios referentes aos estágios do desenvolvimento do gametófito masculino foram comparados com os resultados deste estudo. Abstract in english In this study, ultrastructures of anther wall and sporogenous tissue of Leucojum aestivum were investigated during different developmental stages. Cytomictic channels were seen between pollen mother cells during prophase I. Polar distribution was described in the organelle content of pollen mother c [...] ells and microspores in early phases of microsporogenesis and also in pollen mitosis. Active secretion was observed in tapetal cells. Previous reports about developmental stages of male gametophyte were compared with the results of this study.

Ekici, Nuran; Dane, Feruzan.

362

Does singlet oxygen activate cell death in Arabidopsis cell suspension cultures?: Analysis of the early transcriptional defense responses to high light stress  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Can Arabidopsis cell suspension cultures (ACSC) provide a useful working model to investigate genetically-controlled defense responses with signaling cascades starting in chloroplasts? In order to provide a convincing answer, we analyzed the early transcriptional profile of Arabidopsis cells at high light (HL). The results showed that ACSC respond to HL in a manner that resembles the singlet oxygen (1O2)-mediated defense responses described for the conditional fluorescent (flu) mutant of Arab...

Gutie?rrez, Jorge; Gonza?lez-pe?rez, Sergio; Garci?a-garci?a, Francisco; Lorenzo, O?scar; Arellano, Juan B.

2011-01-01

363

Potentialités androgénétiques du palmier dattier Phoenix dactylifera L. et culture in vitro d'anthères  

Directory of Open Access Journals (Sweden)

Full Text Available Genetic potentialities if five male date palm genotypes, and in vitro culture of anthers. The experimental results derived from the study of five date palm (Phoenix dactylifera L. genotypes indicate that the ability of microspores to divide varies with genotype and culture medium. The highest frequency of microspore division is obtained with the induction medium [Murashige and Skoog (MS 1962 mineral elements, 2,4-dichlorophenoxyacetique (2,4-D, 2-isopentenylaminopurine (2-IP] containing activated charcoal. The pollinator T106 was considered as the most efficient genotype in our experimentation

Harzallah H.

2002-01-01

364

The Effects of an Integrated Reading Comprehension Strategy: A Culturally Responsive Teaching Approach for Fifth-Grade Students' Reading Comprehension  

Science.gov (United States)

The study evaluated the effects of the Integrated Reading Comprehension Strategy on two levels. The Integrated Reading Comprehension Strategy integrated story grammar instruction and story maps, prior knowledge and prediction method, and word webs through a culturally responsive teaching framework; the Integrated Reading Comprehension Strategy…

Bui, Yvonne N.; Fagan, Yvette M.

2013-01-01

365

More than Being Green: A Response to Mike Mueller's Review of "Transforming Environmental Education: Making the Cultural and Environmental Commons the Focus of Educational Reform"  

Science.gov (United States)

In this article, the author offers a response to Mike Mueller's review of "Transforming Environmental Education: Making the Cultural and Environmental Commons the Focus of Educational Reform." Mueller's review, although limited in the way all reviews are limited, makes a genuine contribution by not imposing interpretations that reflect the…

Bowers, C. A.

2008-01-01

366

Response coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Although the production of poly-?-hydroxybutyrate (PHB has many biological, energetic and environmental advantages over chemically synthesized polymers, synthetic polymers continue to be produced industrially since the productivities of fermentation processes fr PHB are not yet economically competitive. Improvement of a PHB fermentation requires good understanding and optimization under the realistic conditions of large bioreactors. Laboratory-scale studies have shown that co-cultures of Ralstonia eutropha and Lactobacillus delbrueckii generate better fermentation efficiencies than R. eutropha alone. In large bioreactors, incomplete dispersioin and perturbations in the dissolved oxygen (DO concentration, both of which affect the fermentation, have to be considered. This study analyzes the effect of DO fluctuations on bioreactor performance for both ideal and optimally dispersed broths. Results Response coefficient analysis was employed to obtain quantitative information on the effect of DO perturbations on different variables. Three values of the Peclet number (Pe cheracterized three levels of dispersion: Pe = 0.01 for nearly complete dispersion, Pe = 20 for optimum dispersion and Pe = 60 for insufficient dispersion. The response coefficients (RCs of the pairs of bacterial concentrations and the main substrates, glucose and ammonium chloride, showed contrasting variations with time. Lactate, a critical intermediate, and PHB had similar RC profiles but those of lactate were one to two orders of magnitude larger than other RCs. Significantly, the optimum Pe also resulted in the largest RCs, suggesting a balance between productivity and reactor stability. Conclusion Since R. eutropha requires oxygen for its growth whereas L. delbrueckii does not, fluctuations in the DO concentartion have a strong influence on the fermentation. Apart from this, the mechanism of PHB biosynthesis indicates that control of lactate is a critical determinant of fermentation efficiency. The RC profiles indicate that, under non-ideal conditions, a compromise may be required between PHB formation and reactor stability, especially in the latter half of the process.

Patnaik Pratap R

2008-03-01

367

Effects of complexation with in vivo enhancing monoclonal antibodies on activity of growth hormone in two responsive cell culture systems.  

Science.gov (United States)

We describe the properties of three monoclonal antibodies (MAbs) to ovine GH, two of which have previously been shown to enhance, in vivo, the biological activity of bovine and ovine growth hormone. We have examined the effects of these MAbs on GH activity in two appropriate GH-responsive cell culture systems, investigating both acute signalling effects (Janus-activated kinase (Jak)-2 tyrosine phosphorylation -5 min) and longer-term (MTT-formazan production -24 h) effects of hormone-antibody complexes. In the 3T3-F442A pre-adipocyte cell line (which has been demonstrated to be GH responsive), we show that complexation of recombinant bovine (rb) GH with either of the two enhancing anti-ovine GH MAbs (OA11 and OA15) and the non-enhancing MAb, OA14, attenuates the ability of GH to stimulate tyrosine phosphorylation of Jak-2 at a 5-min time point. Using the mouse myeloid cell line, FDC-P1, stably transfected with the full-length ovine GH receptor (oGHR), we demonstrate that rbGH causes a dose-dependent increase in MTT-formazan production by these cells. Further, we demonstrate that OA11 and OA14, but not OA15, cause a decrease in this stimulatory activity of rbGH over a hormone concentration range of 5-50 ng/ml at both 24 and 48 h. We conclude that the different in vitro activities of the two in vivo enhancing MAbs are most probably related to the time-courses over which these two assays are performed, and also to the relative affinities between antibody, hormone and receptor. In addition, the in vitro inhibitory activity of the enhancing MAb OA11 in both short- and long-term bioassay lends further support to an exclusively in vivo model for MAb-mediated enhancement of GH action. PMID:10601976

Beattie, J; Borromeo, V; Bramani, S; Secchi, C; Baumbach, W R; Mockridge, J

1999-12-01

368

Anatomical Responses of Roots in Trifoliate Orange Budded with Satsuma Mandarin to Aerated and Stagnant Culture Solutions  

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Full Text Available Anatomical responses of roots in trifoliate orange budded with satsuma mandarin (Citrus unshiu Marc. cv. Okitsu Wase to aerated and stagnant culture solutions were investigated. Roots, under aerated condition, had sharply pointed tips and showed intact anatomical features having a few starch grains on the rootcap and cortical cells. The cortical cells were smaller close to the root tip and gradually became elongated towards the base. All these characteristics maintained the same level even up to 10 days of observations. On the contrary, under stagnant condition, secretion of mucilaginous substances and root tip injuries were found on the 3rd day of induction which became more conspicuous on the 5th. These injuries resulted the severe sloughing of cells and starch grain degradation in the rootcap. Eight day induced roots displayed more distinct root tip injuries and discharging of mucilaginous substances. On the 10th day, air spacing between the cortical cells were conspicuous. Epidermal injuries were also evidenced sporadically on the 5th day and became more severe subsequently. Degradation of starch grains gradually completed in the cortical cells along the exposure time. The enlargement of periblemic cells were noticed which gradually resulted larger cells close to the root apex on longer exposures.

Pear Mohammad

1999-01-01

369

Characteristics and mechanisms of the bystander response in monolayer cell cultures exposed to very low fluences of alpha particles  

International Nuclear Information System (INIS)

When confluent cultures of mammalian cells are irradiated with very low fluences of alpha particles whereby only occasional cells receive any radiation exposure, genetic changes are observed in the non-irradiated ('bystander') cells. Upregulation of the p53 damage-response pathway as well as activation of proteins in the MAPK family occurred in bystander cells; p53 was phosphorylated on the serine 15 residue suggesting that the upregulation of p53 was a consequence of DNA damage. Damage signals were transmitted to bystander cells through gap junctions, as confirmed by the use of genetically manipulated cells including connexin43 knockouts. Expression of connexin43 was markedly enhanced by irradiation. A moderate bystander effect was observed for specific gene mutations and chromosomal aberrations. This effect was markedly enhanced in cells defective in the non-homologous end joining DNA repair pathway. Finally, an upregulation of oxidative metabolism occurred in bystander cells; the increased levels of reactive oxygen species appeared to be derived from flavine-containing oxidase enzymes. We hypothesize that genetic effects observed in non-irradiated bystander cells are a consequence of oxidative base damage; >90% of mutations in bystander cells were point mutations. When bystander cells cannot repair DNA double strand breaks, they become much more sensitive to the induction of chromosomal aberrations and mutations, the latter consisting primarily of deletion mutants. While we propose that the genetic effects occurring in bystander cells are a consequence of oxidative stress, the nature of the signal that initiates this process remains to be determined

2005-02-01

370

Transcriptional response of soybean suspension-cultured cells induced by Nod factors obtained from Bradyrhizobium japonicum USDA110.  

Science.gov (United States)

Genes responding to Nod factors were picked up by the application of a differential display method for soybean suspension-cultured cells. Forty-five cDNA fragments derived from such genes were detected. Seven fragments (ssc1-ssc7) were successfully cloned. The putative product of genes corresponding to ssc1 was estimated to be a disease-resistance protein relating to the induction of the plant defense response against pathogens, and that corresponding to ssc7 was a sucrose transporter. Amino acid sequences deduced from full-length cDNA corresponding to ssc2 and ssc4 were investigated, and it was shown that these polypeptides were equipped with a leucine zipper motif and with phosphorylation sites that were targeted by tyrosin kinase and cAMP-dependent protein kinase, respectively. In a differential display experiment, the transcriptional levels of three genes corresponding to ssc2, ssc3 and ssc5 were estimated to be up-regulated at 6 h after initiation of the treatment and the remaining four were estimated to be down-regulated. However, transcription of the genes corresponding to all ssc was clearly repressed within 2 h after initiation of the treatment. Five of them were restored to their transcriptional level 6 h after initiation of the treatment, although the others were repressed throughout the experimental period. PMID:12461131

Hakoyama, Tsuneo; Yokoyama, Tadashi; Kouchi, Hiroshi; Tsuchiya, Ken-ichi; Kaku, Hisatoshi; Arima, Yasuhiro

2002-11-01

371

Characteristics and mechanisms of the bystander response in monolayer cell cultures exposed to very low fluences of alpha particles  

Science.gov (United States)

When confluent cultures of mammalian cells are irradiated with very low fluences of alpha particles whereby only occasional cells receive any radiation exposure, genetic changes are observed in the non-irradiated ("bystander") cells. Upregulation of the p53 damage-response pathway as well as activation of proteins in the MAPK family occurred in bystander cells; p53 was phosphorylated on the serine 15 residue suggesting that the upregulation of p53 was a consequence of DNA damage. Damage signals were transmitted to bystander cells through gap junctions, as confirmed by the use of genetically manipulated cells including connexin43 knockouts. Expression of connexin43 was markedly enhanced by irradiation. A moderate bystander effect was observed for specific gene mutations and chromosomal aberrations. This effect was markedly enhanced in cells defective in the non-homologous end joining DNA repair pathway. Finally, an upregulation of oxidative metabolism occurred in bystander cells; the increased levels of reactive oxygen species appeared to be derived from flavine-containing oxidase enzymes. We hypothesize that genetic effects observed in non-irradiated bystander cells are a consequence of oxidative base damage; >90% of mutations in bystander cells were point mutations. When bystander cells cannot repair DNA double strand breaks, they become much more sensitive to the induction of chromosomal aberrations and mutations, the latter consisting primarily of deletion mutants. While we propose that the genetic effects occurring in bystander cells are a consequence of oxidative stress, the nature of the signal that initiates this process remains to be determined.

Little, John B.; Azzam, Edouard I.; de Toledo, Sonia M.; Nagasawa, Hatsumi

2005-02-01

372

Characterization of a Collection of Brassica carinata Genotypes for in vitro Culture Response and Mode of Shoot Regeneration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Brassica carinata, a natural alloploid formed between B. oleracea and B. nigra, is a potential oil crop for the Mediterranean area in which genetic transformation could help to breeding. In vitro culture and shoot regeneration are key factors in developing an efficient transformation method in the genus Brassica. However, the studies for in vitro culture and shoot regeneration in B. carinata are limited to only a few genotypes. The aim of this study was to evaluate the in vitro culture respon...

Javier Gil-Humanes; Antonio Martín; Francisco Barro

2011-01-01

373

Culture, Gender and Health Care Stigma: Practitioners’ Response to Facial Masking Experienced by People with Parkinson’s Disease  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Facial masking in Parkinson’s disease is the reduction of automatic and controlled expressive movement of facial musculature, creating an appearance of apathy, social disengagement or compromised cognitive status. Research in western cultures demonstrates that practitioners form negatively biased impressions associated with patient masking. Socio-cultural norms about facial expressivity vary according to culture and gender, yet little research has studied the effect of these factors on prac...

Tickle-degnen, Linda; Zebrowitz, Leslie A.; Ma, Hui-ing

2011-01-01

374

Security culture in Germany  

International Nuclear Information System (INIS)

The standing of the terms 'security' and 'culture' will be discussed. A brief overview about states and operators responsibilities linked to security culture will be given, and a definition of the term 'security culture' will be explained. The security culture in German nuclear facilities will be briefly discussed

2003-11-25

375

Effects of inhibitors of protein kinase C and NO-synthase on the radiation-induced cytogenetic adaptive response in Chinese hamster cells in culture  

International Nuclear Information System (INIS)

The effect of the serine-threonin kinase inhibitor - staurosporine and inhibitor of NO-synthase - L-NAME on the radiation-induced adaptive response were studied in fibroblasts of Chinese hamster in culture. It is shown that staurosporine and L-NAME inhibit cytogenetic adaptive response induced by ?-particles in low doses. Inhibition is not connected with radiosensitizing effect of these agents. L-NAME decreases significantly the ?-rays-induced chromosome aberration yield also. Study confirms the role of protein kinase C in induction of the adaptive response and participation of NO-synthase in this process is noticed for the first time

2001-01-01

376

Prospective study on adaptive response induction by heavy-ion radiation in human lymphoblastoid cell lines and cultured mouse fetal cells  

International Nuclear Information System (INIS)

We investigated radiation-induced response to X-rays and heavy-ions in lymphoblastoid cells. As pre-exposure to low priming dose of ionizing radiations decreases the biological effects of a subsequent higher challenging dose in a variety of models, we wondered whether adaptive response could be observed when using accelerated heavy ions radiation. For the first time, we demonstrated the existence of a mutagenic adaptive response to both low and high-linear energy transfer (LET) radiation in cultured human lymphoblastoid cells, which might be linked with a modulation of DNA repair. (author)

2009-06-01

377

Quantitative Nuclease Protection Assays (qNPA) as Windows into Chemical-Induced Adaptive Response in Cultures of Primary Human Hepatocytes (Concentration and Time-Response)  

Science.gov (United States)

Cultures of primary human hepatocytes have been shown to be dynamic in vitro model systems that retain liver-like functionality (e.g. metabolism, transport, induction). We have utilized these culture models to interrogate 309 ToxCast chemicals. The study design characterized both...

378

Comparative study of predatory responses in blue mussels (Mytilus edulis L.) produced in suspended long line cultures or collected from natural bottom mussel beds  

DEFF Research Database (Denmark)

Blue mussels (Mytilus edulis L.) are a valuable resource for commercial shellfish production and may also have uses as a tool in habitat improvement, because mussel beds can increase habitat diversity and complexity. A prerequisite for both commercial mussel production and habitat improvement is the availability of seed mussels collected with minimum impact on the benthic ecosystem. To examine whether mussels collected in suspended cultures can be used for bottom culture production and as tool in habitat improvement, the differences in predatory defence responses between suspended and bottom mussels exposed to the predatory shore crab (Carcinus maenas L.) were tested in laboratory experiments and in the field. Predatory defence responses (byssal attachment and aggregation) and morphological traits were tested in laboratory, while growth and mortality were examined in field experiments. Suspended mussels had an active response in relation to the predator by developing a significantly firmer attachment to the substrate and a closer aggregated structure. Bottom mussels had a passive strategy by having a thicker shell and larger relative size of the adductor muscle. In a field experiment mussels originated from suspended cultures had a higher length increment and lower mortality when compared to bottom mussels. It is concluded that suspended mussels potentially are an alternative resource to bottom culture and can be used in habitat improvement of mussel beds, but that the use of suspended mussels has to be tested further in large-scale field experiments

Christensen, Helle Torp; Dolmer, Per

2011-01-01

379

Tropism and Innate Host Responses of the 2009 Pandemic H1N1 Influenza Virus in ex Vivo and in Vitro Cultures of Human Conjunctiva and Respiratory Tract  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The novel pandemic influenza H1N1 (H1N1pdm) virus of swine origin causes mild disease but occasionally leads to acute respiratory distress syndrome and death. It is important to understand the pathogenesis of this new disease in humans. We compared the virus tropism and host-responses elicited by pandemic H1N1pdm and seasonal H1N1 influenza viruses in ex vivo cultures of human conjunctiva, nasopharynx, bronchus, and lung, as well as in vitro cultures of human nasopharyngeal, bronchial, and al...

Chan, Michael C. W.; Chan, Renee W. Y.; Yu, Wendy C. L.; Ho, Carol C. C.; Yuen, Kit M.; Fong, Joanne H. M.; Tang, Lynsia L. S.; Lai, Wico W.; Lo, Amy C. Y.; Chui, W. H.; Sihoe, Alan D. L.; Kwong, Dora L. W.; Wong, David S. H.; Tsao, George S. W.; Poon, Leo L. M.

2010-01-01