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581.
Nikolaos Sfakianakis Niklas Kolbe Nadja Hellmann Mária Lukáčová-Medvid’ová 《Bulletin of mathematical biology》2017,79(1):209-235
We propose a multiscale model for the invasion of the extracellular matrix by two types of cancer cells, the differentiated cancer cells and the cancer stem cells. We investigate the epithelial mesenchymal-like transition between them being driven primarily by the epidermal growth factors. We moreover take into account the transdifferentiation program of the cancer stem cells towards the cancer-associated fibroblast cells as well as the fibroblast-driven remodelling of the extracellular matrix. The proposed haptotaxis model combines the macroscopic phenomenon of the invasion of the extracellular matrix by both types of cancer cells with the microscopic dynamics of the epidermal growth factors. We analyse our model in a component-wise manner and compare our findings with the literature. We investigate pathological situations regarding the epidermal growth factors and accordingly propose “mathematical-treatment” scenarios to control the aggressiveness of the tumour. 相似文献
582.
583.
Anika Nadja Sabine Prange Margrethe Serek Melanie Bartsch Traud Winkelmann 《Plant Cell, Tissue and Organ Culture》2010,101(2):171-182
Embryogenic cultures of Cyclamen coum were established on solid media and in suspension, and their growth characteristics in response to different concentrations
of plant growth regulators (PGRs) were evaluated. Embryogenic cultures exhibited a high regeneration capacity of 876 somatic
embryos per gram fresh mass. Up to 4.24 × 105 protoplasts per gram of fresh mass were isolated from somatic embryos and embryogenic suspension cultures. Protoplasts derived
from both embryos and suspension cultures were successfully cultured in vitro and regenerated into plants via somatic embryogenesis.
Phenotypic analyses and flow cytometric measurements revealed that some regenerated plants were tetraploid. About 20% of the
protoplast-derived calluses used for regeneration were tetraploid, while tetraploidy was found in 0.9% of the plants regenerated
from the embryogenic cultures. 相似文献
584.
585.
Nadja Verspagen Suvi Ikonen Marjo Saastamoinen Erik van Bergen 《Proceedings. Biological sciences / The Royal Society》2020,287(1941)
Variation in environmental conditions during development can lead to changes in life-history traits with long-lasting effects. Here, we study how variation in temperature and host plant (i.e. the consequences of potential maternal oviposition choices) affects a suite of life-history traits in pre-diapause larvae of the Glanville fritillary butterfly. We focus on offspring survival, larval growth rates and relative fat reserves, and pay specific attention to intraspecific variation in the responses (G × E × E). Globally, thermal performance and survival curves varied between diets of two host plants, suggesting that host modifies the temperature impact, or vice versa. Additionally, we show that the relative fat content has a host-dependent, discontinuous response to developmental temperature. This implies that a potential switch in resource allocation, from more investment in growth at lower temperatures to storage at higher temperatures, is dependent on the larval diet. Interestingly, a large proportion of the variance in larval performance is explained by differences among families, or interactions with this variable. Finally, we demonstrate that these family-specific responses to the host plant remain largely consistent across thermal environments. Together, the results of our study underscore the importance of paying attention to intraspecific trait variation in the field of evolutionary ecology. 相似文献
586.
587.
Avoidance of precipitation and carbohydrate breakdown in autoclaved plant tissue culture media 总被引:2,自引:0,他引:2
The extent of breakdown of fructose and glucose derived from sucrose in the medium of Murashige and Skoog (1962) during autoclaving was investigated by polarographic measurement. Although not present in the original MS medium but often used in place of FeSO4 + Na2-EDTA, FeNa-EDTA was found to be primarily responsible for catalyzing the breakdown of these monosaccharides. It would therefore be good practice to autoclave FeNa-EDTA separate from the carbohydrate constituents of the medium in order to reduce the formation of toxic substances derived from the latter's breakdown. Autoclaving FeNa-EDTA separately has the additional advantage of preventing precipitation of certain micronutrient elements. Further precipitation can be avoided by autoclaving FeNa-EDTA and KH2PO4 together, but separately, from other components of the medium. By eliminating precipitation and minimizing the breakdown of monosaccharides during autoclaving, it is possible to improve the quality of the medium without resorting to sterilization by filtering.Abbreviations HMF
5-(hydroxymethyl)-2-furaldehyde
- FeNa-EDTA
ferric monosodium ethylenediaminetetraacetic acid
- MS
Murashige and Skoog
- NAA
naphthylacetic acid 相似文献
588.
589.
Guido Bonthond Till Bayer Stacy A. Krueger-Hadfield Nadja Strck Gaoge Wang Masahiro Nakaoka Sven Künzel Florian Weinberger 《The ISME journal》2021,15(6):1668
Invasive species are co-introduced with microbiota from their native range and also interact with microbiota found in the novel environment to which they are introduced. Host flexibility toward microbiota, or host promiscuity, is an important trait underlying terrestrial plant invasions. To test whether host promiscuity may be important in macroalgal invasions, we experimentally simulated an invasion in a common garden setting, using the widespread invasive macroalga Agarophyton vermiculophyllum as a model invasive seaweed holobiont. After disturbing the microbiota of individuals from native and non-native populations with antibiotics, we monitored the microbial succession trajectories in the presence of a new source of microbes. Microbial communities were strongly impacted by the treatment and changed compositionally and in terms of diversity but recovered functionally by the end of the experiment in most respects. Beta-diversity in disturbed holobionts strongly decreased, indicating that different populations configure more similar –or more common– microbial communities when exposed to the same conditions. This decline in beta-diversity occurred not only more rapidly, but was also more pronounced in non-native populations, while individuals from native populations retained communities more similar to those observed in the field. This study demonstrates that microbial communities of non-native A. vermiculophyllum are more flexibly adjusted to the environment and suggests that an intraspecific increase in host promiscuity has promoted the invasion process of A. vermiculophyllum. This phenomenon may be important among invasive macroalgal holobionts in general.Subject terms: Symbiosis, Molecular ecology, Microbial ecology 相似文献
590.
Abstract Non-acid and acid glycolipids were isolated from the small intestine of a newborn calf and tested for the ability to bind Escherichia coli carrying K99 fimbriae. The bacteria did not bind to any of the non-acid glycolipids, whereas in the acid glycolipid fraction several gangliosides were detected which bind to K99 fimbriae. Gangliosides capable of binding K99 fimbriated E. coli were characterized as NeuGc-GM3, NeuGc-GM2, NeuGc-GD1a NeuAc-SPG and NeuAc-SPG. No binding was detected to NeuAc-GM3 and NeuGc-GM1. 相似文献