scholarly journals Nutritional and seasonal requirements for callus growth in Taxus baccata

2000 ◽  
Vol 6 (4) ◽  
Author(s):  
K. Brunáková ◽  
Z. Babincová ◽  
E. Cellárová
Keyword(s):  
Growth Rate ◽  
Callus Cultures ◽  
Stem Explants ◽  
Taxus Baccata ◽  
Plant Genotype ◽  
Genotype I ◽  
Defined Media ◽  
Genotype Ii

Callus cultures derived from young stems of two varieties of Taxus baccata cv. aureovariegata (genotype I) and Taxus baccata L. (genotype II, III) were induced. Gamborg's B5 medium was supplemented with different concentrations of auxin (2,4-D) in combination with cytokinins (kinetin or topolin) and with a phenolic-binding compound (PVP) to prevent callus darkening and growth inhibition. Stem explants displayed different responses to in vitro culture depending on plant genotype and on the season. Genetic variability was observed in the growth rate of calli initiated from all three genotypes of the same Taxus species. We found the best growth of callus cultures originated from the genotype ill in defined media. After the first subculture the majority of the cream-coloured primary callus turned brown and ceased its growth. However, the long-term culture was initiated.  

scholarly journals Morphologial variation in colonies of Chalara fraxinea isolated from ash (Fraxinus excelsior L.) stems with symptoms of dieback and effects of temperature on colony growth and structure

2012 ◽  
Vol 63 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Tadeusz Kowalski ◽  
Czesław Bartnik
Keyword(s):  
Growth Rate ◽  
Colony Growth ◽  
Malt Extract ◽  
Optimum Temperature ◽  
Ash Trees ◽  
Effects Of Temperature ◽  
Main Factor

The present paper presents the results of long-term observations of differences in growth and morphology of colonies of <i>C. fraxinea</i> isolated from ash stems with symptoms of dieback and the results of studies on effects of temperature on growth and morphology of colonies <i>in vitro</i>. Thirty randomly chosen <i>C. fraxinea</i> cultures, originating from six Forest Districts in southern and northern Poland, viz. Andrychów, Gryfice, Kańczuga, Lębork, Miechów and Mircze, were included in the temperature assay. Colony growth and morphology were evaluated <i>in vitro</i>, on malt extract agar. Two replicates of each isolate were incubated at 5, 10, 15, 20, 25 and 30°C in darkness. Colonies of <i>C. fraxinea</i> isolated from necrotic stem tissues of diseased ash trees differed greatly in colour, structure, growth rate, presence of sectors and stromata as well as the intensity of conidial sporulation. Colony characters were often lost in further sub-cultures grown on the same medium. Colonies of <i>C. fraxinea</i> grew at 5-25°C <i>in vitro</i>. Three isolates still grew, though slowly, at 30°C. The optimum temperature for growth was 20°C. Among 30 isolates tested, five grew most quickly at 25°C and four at 15°C. Differences among colony diameters recorded at 5, 10, 15, 20 and 30°C were statistically significant, while differences at 15 and 25°C were not. At some temperatures, statistically significant differences in growth rate were related to the origin of the isolates. There were three main colony colour types. Temperature was the main factor affecting colony morphology <i>in vitro</i>. The formation of sectors was observed in 36% of colonies, pseudoparenchymatous stromata in 10.4% of colonies, and white crystalline substances in 53.3% of colonies. The results of <i>in vitro</i> observations were used for discussion of the effects of temperature on growth and activity of <i>C. fraxinea</i> <i>in vivo</i>.

scholarly journals Rapid emergence of clonal interference during malaria parasite cultivation

2020 ◽  
Author(s):  
Catherine Jett ◽  
Aliou Dia ◽  
ian H. cheeseman
Keyword(s):  
Growth Rate ◽  
Malaria Parasite ◽  
Time Frame ◽  
Genomic Variation ◽  
Clonal Interference ◽  
Long Term Culture ◽  
Parasite Plasmodium Falciparum ◽  
Cell Genome

Abstract Laboratory cultivation of the malaria parasite Plasmodium falciparum has underpinned nearly all advances in malariology in the past 30 years. When freshly isolated clinical isolates are adapted to in vitro culture mutations rapidly fix increasing the parasite growth rate and stability. While the dynamics of culture adaptation are increasingly well characterized, we know little about the extent of genomic variation that arises and spreads during long term culture. To address this we cloned the 3D7 reference strain and maintained a culture for ~84 asexual cycles (167 days). Growth rate of the culture population increased 1.14-fold over this timeframe. We used single cell genome sequencing of parasites at cycles 21 and 84 to measure the accumulation of diversity in vitro . This parasite population showed strong signals of adaptation across this time frame. By cycle 84 two dominant clades had arisen and were segregating with the dynamics of clonal interference. This highlights the continual process of adaptation in malaria parasites, even in parasites which have been extensively adapted to long term culture.

The FRTL-5 thyroid cell strain as a model for studies on thyroid cell growth

1987 ◽  
Vol 116 (1_Suppl) ◽  
pp. S242-S245 ◽  
Author(s):  
Francesco Saverio Ambesi-Impiombato ◽  
Giovanni Villone
Keyword(s):  
Cell Proliferation ◽  
Cell Growth ◽  
Cell Strain ◽  
Thyroid Cell ◽  
In Vitro System ◽  
Defined Media ◽  
Thyroid Follicular Cells ◽  
Rat Thyroid

Abstract. Thyroid cell proliferation has been studied using an in vitro system of rat thyroid follicular cell strain (FRTL-5). While growing in continuous culture, this strain is still differentiated and non-tumourigenic. Both advantages and limitations in the use of such system for studies of thyroid cell growth should be considered. Some obvious limitations should be considered, such as the species (rat) from which FRTL-5 cells were originated, their long-term growth outside the animals, the presence of a chronic TSH stimulation. On the other hand, several advantages as the growth in hormonally and chemically defined media, their dependence upon TSH in the medium, their genetic homogeneity and their widespread use in many laboratories render the FRTL-5 strain a useful experimental tool. Studies on cell proliferation and mechanism of action of hormones, growth factors and human autoimmune IgG have been and are being performed, with the assumption that FRTL-5 cells are the in vitro equivalent of thyroid follicular cells.

scholarly journals The Stringent Response of Mycobacterium tuberculosis Is Required for Long-Term Survival

2000 ◽  
Vol 182 (17) ◽  
pp. 4889-4898 ◽  
Author(s):  
Todd P. Primm ◽  
Susan J. Andersen ◽  
Valerie Mizrahi ◽  
David Avarbock ◽  
Harvey Rubin ◽  
...  
Keyword(s):  
Growth Rate ◽  
Mycobacterium Tuberculosis ◽  
Stringent Response ◽  
Wild Type ◽  
Liquid Media ◽  
Term Survival ◽  
Long Term Survival ◽  
Starvation Conditions

ABSTRACT The stringent response utilizes hyperphosphorylated guanine [(p)ppGpp] as a signaling molecule to control bacterial gene expression involved in long-term survival under starvation conditions. In gram-negative bacteria, (p)ppGpp is produced by the activity of the related RelA and SpoT proteins. Mycobacterium tuberculosis contains a single homolog of these proteins (RelMtb) and responds to nutrient starvation by producing (p)ppGpp. A relMtb knockout strain was constructed in a virulent strain of M. tuberculosis, H37Rv, by allelic replacement. The relMtb mutant displayed a significantly slower aerobic growth rate than the wild type in synthetic liquid media, whether rich or minimal. The growth rate of the wild type was equivalent to that of the mutant when citrate or phospholipid was employed as the sole carbon source. These two organisms also showed identical growth rates within a human macrophage-like cell line. These results suggest that the in vivo carbon source does not represent a stressful condition for the bacilli, since it appears to be utilized in a similar RelMtb-independent manner. In vitro growth in liquid media represents a condition that benefits from RelMtb-mediated adaptation. Long-term survival of therelMtb mutant during in vitro starvation or nutrient run out in normal media was significantly impaired compared to that in the wild type. In addition, the mutant was significantly less able to survive extended anerobic incubation than the wild-type virulent organism. Thus, the RelMtb protein is required for long-term survival of pathogenic mycobacteria under starvation conditions.

scholarly journals The 16-kDa α-crystallin (Acr) protein ofMycobacterium tuberculosisis required for growth in macrophages

1998 ◽  
Vol 95 (16) ◽  
pp. 9578-9583 ◽  
Author(s):  
Ying Yuan ◽  
Deborah D. Crane ◽  
R. Mark Simpson ◽  
YaQi Zhu ◽  
Mark J. Hickey ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Growth Rate ◽  
Mouse Bone Marrow ◽  
Hygromycin Resistance ◽  
Wild Type ◽  
Allelic Exchange ◽  
Hypoxic Conditions ◽  
Asymptomatic Infections

Although the 16-kDa α-crystallin homologue ofMycobacterium tuberculosis(MTB) is the dominant protein produced by stationary phase culturesin vitro, it is undetectable in logarithmically growing cultures. By growing bacilli at defined oxygen concentrations,acrtranscription was shown to be strongly induced by mildly hypoxic conditions. Acr expression also was found to be induced during the course ofin vitroinfection of macrophages. Theacrgene was replaced with a hygromycin resistance cassette by allelic exchange in MTB H37Rv. The resulting Δacr∷hptstrain was shown to be equivalent to wild-type H37Rv inin vitrogrowth rate and infectivity but was significantly impaired for growth in both mouse bone marrow derived macrophages and THP-1 cells. In addition to its proposed role in maintenance of long-term viability during latent, asymptomatic infections, these results establish a role for the Acr protein in replication during initial MTB infection.

In vitro selection of glyphosate-tolerant variants from long-term callus cultures of Zoysia matrella [L.] Merr

2012 ◽  
Vol 111 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Shu Chen ◽  
Mingliang Chai ◽  
Yufang Jia ◽  
Zhongshan Gao ◽  
Li Zhang ◽  
...  
Keyword(s):  
In Vitro Selection ◽  
Callus Cultures ◽  
Zoysia Matrella ◽  
Selection Of

scholarly journals In vitro selection of birch for tolerance to salinity stress

2021 ◽  
Vol 875 (1) ◽  
pp. 012082
Author(s):  
O S Mashkina ◽  
T M Tabatskaya ◽  
O M Korchagin
Keyword(s):  
Betula Pendula ◽  
In Vitro Selection ◽  
Callus Formation ◽  
Callus Cultures ◽  
Cellular Heterogeneity ◽  
Stem Explants ◽  
Salt Tolerant ◽  
Tolerance To Salinity ◽  
Selection Of

Abstract In vitro modelling of stress is one of the promising avenues for plant breeding for tolerance to negative environmental factors. In this study we examined the effect of NaCl (0.5%) on callusogenesis and morphogenesis of stem explants of different birch genotypes: Betula pendula Roth, B. pendula Roth var. carelica (Mercklin) Hämet-Ahti, B. pendula f. ‘dalecarlica’ (L.f.) Schneid., B. pubescens Ehrh. In our experiments we used pre-selected microclones from our in vitro collection on NaCl (0.2-1.0%) selective media. The clones were contrasted by the degree of their sensitivity to salinity (so-called ‘stable’ and ‘sensitive’ microclones). With the use of stem callus cultures we identified informative, simple and reproducible indicators for the selection of salt-tolerant genotypes. Among these indicators were the frequency of callus formation and the viability of callus cultures, which were significantly higher in ‘stable’ group of microclones. Polyploid birch clones (2n=4x=56, 2n=3x=42) were more resistant to salination compared to diploid clones (2n=28). Our study has shown that the selection of salt-tolerant birch lines can be based on the plants’ genetic diversity presented in the collection (various species, varieties, hybrids, polyploids) and manifested in the process of in vitro cultivation, as well as in the cellular heterogeneity of callus cultures.

scholarly journals Host Cell Tropism Underlies Species Restriction of Human and Bovine Cryptosporidium parvum Genotypes

2004 ◽  
Vol 72 (10) ◽  
pp. 6125-6131 ◽  
Author(s):  
Amna Hashim ◽  
Marguerite Clyne ◽  
Grace Mulcahy ◽  
Donna Akiyoshi ◽  
Rachel Chalmers ◽  
...  
Keyword(s):  
Small Bowel ◽  
Epithelial Cells ◽  
Cryptosporidium Parvum ◽  
Intestinal Epithelial Cells ◽  
Specific Cell ◽  
Cell Tropism ◽  
Intestinal Epithelial ◽  
Genotype I ◽  
Genotype Ii

ABSTRACT It has been recognized recently that human cryptosporidiosis is usually caused by Cryptosporidium parvum genotype I (“human” C. parvum), which is not found in animals. Compared to C. parvum genotype II, little is known of the biology of invasion of the human-restricted C. parvum genotype I. The aims of the present study were (i) to explore and compare with genotype II the pathogenesis of C. parvum genotype I infection by using an established in vitro model of infection and (ii) to examine the possibility that host-specific cell tropism determines species restriction among C. parvum genotypes by using a novel ex vivo small intestinal primary cell model of infection. Oocysts of C. parvum genotypes I and II were used to infect HCT-8 cells and primary intestinal epithelial cells in vitro. Primary cells were harvested from human endoscopic small-bowel biopsies and from bovine duodenum postmortem. C. parvum genotype I infected HCT-8 cells with lower efficiency than C. parvum genotype II. Actin colocalization at the host parasite interface and reduction in levels of invasion after treatment with microfilament inhibitors (cytochalasin B and cytochalasin D) were observed for both genotypes. C. parvum genotype II invaded primary intestinal epithelial cells, regardless of the species of origin. In contrast, C. parvum genotype I invaded only human small-bowel cells. The pathogenesis of C. parvum genotype I differs from C. parvum genotype II. C parvum genotype I does not enter primary bovine intestinal cells, suggesting that the species restriction of this genotype is due to host tissue tropism of the infecting isolate.

scholarly journals DJ-1 Can Replace FGF-2 for Long-Term Culture of Human Pluripotent Stem Cells in Defined Media and Feeder-Free Condition

2021 ◽  
Vol 22 (11) ◽  
pp. 5954
Author(s):  
Julee Kim ◽  
Sangki Baek ◽  
Yean-Ju Hong ◽  
Michelle Novais de Paula ◽  
Musharrat Jahan Prima ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem ◽  
Mrna Levels ◽  
Self Renewal ◽  
Free Condition ◽  
Long Term Culture ◽  
Defined Media ◽  
Pluripotency Markers

Conventional human pluripotent stem cell (hPSC) cultures require high concentrations of expensive human fibroblast growth factor 2 (hFGF-2) for hPSC self-renewal and pluripotency in defined media for long-term culture. The thermal instability of the hFGF-2 mandates media change every day, which makes hPSC culture costly and cumbersome. Human DJ-1 (hDJ-1) can bind to and stimulate FGF receptor-1. In this study, for the first time, we have replaced hFGF-2 with hDJ-1 in the essential eight media and maintained the human embryonic stem cells (hESCs), H9, in the defined media at feeder-free condition. After more than ten passages, H9 in both groups still successfully maintained the typical hESC morphology and high protein levels of pluripotency markers, SSEA4, Tra1-60, Oct4, Nanog, and ALP. DNA microarray revealed that more than 97% of the 21,448 tested genes, including the pluripotency markers, Sox2, Nanog, Klf4, Lin28A, Lin28B, and Myc, have similar mRNA levels between the two groups. Karyotyping revealed no chromosome abnormalities in both groups. They also differentiated sufficiently into three germ layers by forming in vitro EBs and in vivo teratomas. There were some variations in the RT-qPCR assay of several pluripotency markers. The proliferation rates and the mitochondria of both groups were also different. Taken together, we conclude that hDJ-1 can replace hFGF-2 in maintaining the self-renewal and the pluripotency of hESCs in feeder-free conditions.

Axenic in vitro culture and molecular characterization of Giardia duodenalis from red deer (Cervus elaphus) and Thomson’s gazelle (Gazella thomsonii)

2014 ◽  
Vol 59 (4) ◽  
Author(s):  
Piotr Solarczyk ◽  
Anna Majewska ◽  
Anna Słodkowicz-Kowalska
Keyword(s):  
Genetic Diversity ◽  
Growth Rate ◽  
Cervus Elaphus ◽  
Red Deer ◽  
Giardia Duodenalis ◽  
In Vitro Cultures ◽  
Short And Long Term

AbstractGiardia duodenalis is an ubiquitous flagellate that infects humans and many species of animals. This species exhibits great biotypic and genetic diversity. In the present study, we established short- and long-term in vitro cultures of G. duodenalis trophozoites originating from red deer and Thomson’s gazelle (artiodactyls) and genetically characterised the isolates by their glutamate dehydrogenase and triose phosphate isomerase gene sequences. The G. duodenalis isolates from red deer and the gazelle represented assemblages A (AIII sub-assemblage) and B. In conclusion, G. duodenalis assemblages and sub-assemblages can be associated with differences in growth rate in vitro cultures.

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