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261.
Morphogenesis is consequence of lots of small coordinated variations that occur during development. In proliferating stages, tissue growth is coupled to changes in shape and organization. A number of studies have analyzed the topological properties of proliferating epithelia using the Drosophila wing disc as a model. These works are based in the existence of a fixed distribution of these epithelial cells according to their number of sides. Cell division, cell rearrangements or a combination of both mechanisms have been proposed to be responsible for this polygonal assembling. Here, we have used different system biology methods to compare images from two close proliferative stages that present high morphological similarity. This approach enables us to search for traces of epithelial organization. First, we show that geometrical and network characteristics of individual cells are mainly dependent on their number of sides. Second, we find a significant divergence between the distribution of polygons in epithelia from mid-third instar larva versus early prepupa. We show that this alteration propagates into changes in epithelial organization. Remarkably, only the variation in polygon distribution driven by morphogenesis leads to progression in epithelial organization. In addition, we identify the relevant features that characterize these rearrangements. Our results reveal signs of epithelial homogenization during the growing phase, before the planar cell polarity pathway leads to the hexagonal packing of the epithelium during pupal stages. 相似文献
262.
Yuki Ito Jose Luis Vela Fumiko Matsumura Hitomi Hoshino Aaron Tyznik Heeseob Lee Enrico Girardi Dirk M. Zajonc Robert Liddington Motohiro Kobayashi Xingfeng Bao Jeanna Bugaytsova Thomas Borén Rongsheng Jin Yinong Zong Peter H. Seeberger Jun Nakayama Mitchell Kronenberg Minoru Fukuda 《PloS one》2013,8(12)
Approximately 10–15% of individuals infected with Helicobacter pylori will develop ulcer disease (gastric or duodenal ulcer), while most people infected with H. pylori will be asymptomatic. The majority of infected individuals remain asymptomatic partly due to the inhibition of synthesis of cholesteryl α-glucosides in H. pylori cell wall by α1,4-GlcNAc-capped mucin O-glycans, which are expressed in the deeper portion of gastric mucosa. However, it has not been determined how cholesteryl α-glucosyltransferase (αCgT), which forms cholesteryl α-glucosides, functions in the pathogenesis of H. pylori infection. Here, we show that the activity of αCgT from H. pylori clinical isolates is highly correlated with the degree of gastric atrophy. We investigated the role of cholesteryl α-glucosides in various aspects of the immune response. Phagocytosis and activation of dendritic cells were observed at similar degrees in the presence of wild-type H. pylori or variants harboring mutant forms of αCgT showing a range of enzymatic activity. However, cholesteryl α-glucosides were recognized by invariant natural killer T (iNKT) cells, eliciting an immune response in vitro and in vivo. Following inoculation of H. pylori harboring highly active αCgT into iNKT cell-deficient (Jα18−/−) or wild-type mice, bacterial recovery significantly increased in Jα18−/− compared to wild-type mice. Moreover, cytokine production characteristic of Th1 and Th2 cells dramatically decreased in Jα18−/− compared to wild-type mice. These findings demonstrate that cholesteryl α-glucosides play critical roles in H. pylori-mediated gastric inflammation and precancerous atrophic gastritis. 相似文献
263.
Pablo García-Gómez Abdellatif Bahaji Samuel Gámez-Arcas Francisco José Muñoz Ángela María Sánchez-López Goizeder Almagro Edurne Baroja-Fernández Kinia Ameztoy Nuria De Diego Lydia Ugena Lukáš Spíchal Karel Doležal Mohammad-Reza Hajirezaei Luis C. Romero Irene García Javier Pozueta-Romero 《Plant, cell & environment》2020,43(10):2551-2570
264.
Commander Lucy Elizabeth Merino-Martín Luis Elliott Carole P. Miller Ben P. Dixon Kingsley Stevens Jason 《Plant and Soil》2020,457(1-2):113-129
Plant and Soil - Understanding limitations to plant recruitment is a key element in devising effective restoration of semi-arid ecosystems: only when these limitations are identified can management... 相似文献
265.
Jennifer J. Scott Luis A. Buatois M. Gabriela Mángano Robin W. Renaut R. Bernhart Owen 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2020,53(1):62-71
Modern burrowing organisms feed on microbial organic matter in matgrounds near hot springs on the margins of Lake Bogoria, a saline alkaline lake in the Kenya Rift Valley. The burrowers produce a low-diversity trace assemblage similar to those produced by undermat miners during the Ediacaran–Cambrian transition. Despite obvious differences in body plans and phylogenetic affinities, these modern animals feed on microbes in similar ways to those inferred for primitive bilaterians. With increasing distance from hot-spring vents, outflow channels and adjacent matgrounds, the diversity and depth of the traces increase and mixgrounds become dominant. This modern extreme environment gives clues for interpreting the heterogeneous early Cambrian seafloor, with: (1) the restriction of ‘pre-agronomic revolution’ matground substrates; and (2) expansion of adjacent ‘post-agronomic revolution’ mixground areas. 相似文献
266.
Demenois Julien Merino-Martín Luis Fernandez Nuñez Nicolas Stokes Alexia Carriconde Fabian 《Plant and Soil》2020,448(1-2):213-229
Plant and Soil - Understanding how soil aggregate stability (MWD) is influenced by microbial diversity and abundance can be crucial for ecological restoration in severely disturbed areas. We... 相似文献
267.
Jing Zhang Mingjian Zhou Zhenglin Ge Jie Shen Can Zhou Cecilia Gotor Luis C. Romero Xingliang Duan Xin Liu Deliang Wu Xianchao Yin Yanjie Xie 《Plant, cell & environment》2020,43(3):624-636
Recent studies have demonstrated that hydrogen sulfide (H2S) produced through the activity of l -cysteine desulfhydrase (DES1) is an important gaseous signaling molecule in plants that could participate in abscisic acid (ABA)-induced stomatal closure. However, the coupling of the DES1/H2S signaling pathways to guard cell movement has not been thoroughly elucidated. The results presented here provide genetic evidence for a physiologically relevant signaling pathway that governs guard cell in situ DES1/H2S function in stomatal closure. We discovered that ABA-activated DES1 produces H2S in guard cells. The impaired guard cell ABA phenotype of the des1 mutant can be fully complemented when DES1/H2S function has been specifically rescued in guard cells and epidermal cells, but not mesophyll cells. This research further characterized DES1/H2S function in the regulation of LONG HYPOCOTYL1 (HY1, a member of the heme oxygenase family) signaling. ABA-induced DES1 expression and H2S production are hyper-activated in the hy1 mutant, both of which can be fully abolished by the addition of H2S scavenger. Impaired guard cell ABA phenotype of des1/hy1 can be restored by H2S donors. Taken together, this research indicated that guard cell in situ DES1 function is involved in ABA-induced stomatal closure, which also acts as a pivotal hub in regulating HY1 signaling. 相似文献
268.
Ifey Alio Mirja Gudzuhn Pablo Pérez García Dominik Danso Marie Charlotte Schoelmerich Uwe Mamat Ulrich E. Schaible J?rg Steinmann Daniel Yero Isidre Gibert Thomas A. Kohl Stefan Niemann Matthias I. Gr?schel Johanna Haerdter Thomas Hackl Christel Vollstedt Mechthild B?meke Richard Egelkamp Rolf Daniel Anja Poehlein Wolfgang R. Streit 《Applied and environmental microbiology》2020,86(24)
269.
The intestinal microbiota has been reported to affect depression, a common mental condition with severe health-related consequences. However, what mediates the effect of the intestinal microbiota on depression has not been well elucidated. We summarize the roles of the mitochondria in eliciting beneficial effects on the gut microbiota to ameliorate symptoms of depression. It is well known that mitochondria play a key role in depression. An important pathogenic factor, namely inflammatory response, may adversely impact mitochondrial functionality to maintain cellular homeostasis. Dysfunction of mitochondria not only affects neuronal function but also reduces neuron cell numbers. We posit that the intestinal microbiota could affect neuronal mitochondrial function through short-chain fatty acids such as butyrate. Brain inflammatory processes could also be affected through the modulation of gut permeability and blood lipopolysaccharide levels. Aberrant mitochondria functionality coupled to adverse cellular homeostasis could be a key mediator for the effect of the intestinal microbiota on the progression of depression. 相似文献
270.