Development in multicellular organisms depends on the ability of individual cells to coordinate their behavior by means of small signaling molecules to form correctly patterned tissues. In plants, a ...unique mechanism of directional transport of the signaling molecule auxin between cells connects cell polarity and tissue patterning and thus is required for many aspects of plant development. Direction of auxin flow is determined by polar subcellular localization of PIN auxin efflux transporters. Dynamic PIN polar localization results from the constitutive endocytic cycling to and from the plasma membrane, but it is not well understood how this mechanism connects to regulators of cell polarity. The Rho family small GTPases ROPs/RACs are master regulators of cell polarity, however their role in regulating polar protein trafficking and polar auxin transport has not been established. Here, by analysis of mutants and transgenic plants, we show that the ROP interactor and polarity regulator scaffold protein ICR1 is required for recruitment of PIN proteins to the polar domains at the plasma membrane. icr1 mutant embryos and plants display an a array of severe developmental aberrations that are caused by compromised differential auxin distribution. ICR1 functions at the plasma membrane where it is required for exocytosis but does not recycle together with PINs. ICR1 expression is quickly induced by auxin but is suppressed at the positions of stable auxin maxima in the hypophysis and later in the embryonic and mature root meristems. Our results imply that ICR1 is part of an auxin regulated positive feedback loop realized by a unique integration of auxin-dependent transcriptional regulation into ROP-mediated modulation of cell polarity. Thus, ICR1 forms an auxin-modulated link between cell polarity, exocytosis, and auxin transport-dependent tissue patterning.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract The use of alternative nutritional sources is an important topic for animal production such as poultry. This study examined the effect of replacing soybean meal with sunflower leaf meal in ...the diet of laying shaver brown pullets. A total of 30 laying birds were assigned to three treatments of 0% (as control group), 10% and 15% MSFLM inclusion. Four eggs per replicate were randomly taken for three consecutive days at two weeks interval for five times, and 18 weeks individuals were selected after 40 days of experimental time. External parameters of the eggs (egg weight, egg length, egg breadth and egg shape index, shell thickness), and body parameters (Final body weight, weight gain), feed intake and hen day production were measured. For egg length, egg breadth and shell thickness showed significant difference (p< 0.05) in from the control birds. Final body weight, weight gain, feed intake and hen day production showed comparable results with values from eggs of birds on control diet. The study revealed the ability of birds to easily utilize the nutrients in the protein sources. MSFLM utilization up to 15% in pullets’ diet revealed no detrimental effect on the performance of the laying birds and the external qualities of eggs produced.
Resumo O uso de fontes nutricionais alternativas é um tópico importante para a produção animal, como a avicultura. Este estudo examinou o efeito da substituição do farelo de soja por farelo de folha de girassol na dieta de frangas marrons barbeadoras poedeiras. Um total de 30 aves poedeiras foram designadas a três tratamentos de 0% (como grupo controle), 10% e 15% de inclusão MSFLM. Quatro ovos por repetição foram retirados aleatoriamente por três dias consecutivos em intervalos de duas semanas por cinco vezes, e indivíduos de 18 semanas foram selecionados após 40 dias do tempo experimental. Parâmetros externos dos ovos (peso do ovo, comprimento do ovo, largura do ovo e índice de forma do ovo, espessura da casca) e parâmetros corporais (peso corporal final, ganho de peso), consumo de ração e produção diária da galinha foram medidos. Para comprimento do ovo, largura do ovo e espessura da casca apresentaram diferença significativa (p <0,05) nas aves controle. Peso corporal final, ganho de peso, consumo de ração e produção de dia de galinha mostraram resultados comparáveis com valores de ovos de aves em dieta controle. O estudo revelou a capacidade das aves de utilizar facilmente os nutrientes das fontes de proteína. A utilização de MSFLM até 15% na dieta das frangas não revelou nenhum efeito prejudicial no desempenho das aves poedeiras e nas qualidades externas dos ovos produzidos.
In this book Ron Amundson examines two hundred years of scientific views on the evolution-development relationship from the perspective of evolutionary developmental biology (evo-devo). This ...perspective challenges several popular views about the history of evolutionary thought by claiming that many earlier authors had made history come out right for the Evolutionary Synthesis. The book starts with a revised history of nineteenth-century evolutionary thought. It then investigates how development became irrelevant with the Evolutionary Synthesis. It concludes with an examination of the contrasts that persist between mainstream evolutionary theory and evo-devo. This book will appeal to students and professionals in the philosophy and history of science, and biology.
From the author of The Emperor of All Maladies, winner of the Pulitzer Prize, and The Gene, a #1 New York Times bestseller, comes his most spectacular book yet, an exploration of medicine and our ...radical new ability to manipulate cells. Rich with Mukherjee's revelatory and exhilarating stories of scientists, doctors, and the patients whose lives may be saved by their work, The Song of the Cell is the third book in this extraordinary writer's exploration of what it means to be human.Mukherjee begins this magnificent story in the late 1600s, when a distinguished English polymath, Robert Hooke, and an eccentric Dutch cloth-merchant, Antonie van Leeuwenhoek looked down their handmade microscopes. What they saw introduced a radical concept that swept through biology and medicine, touching virtually every aspect of the two sciences, and altering both forever. It was the fact that complex living organisms are assemblages of tiny, self-contained, self-regulating units. Our organs, our physiology, our selveshearts, blood, brainsare built from these compartments. Hooke christened them ';cells'. The discovery of cellsand the reframing of the human body as a cellular ecosystemannounced the birth of a new kind of medicine based on the therapeutic manipulations of cells. A hip fracture, a cardiac arrest, Alzheimer's dementia, AIDS, pneumonia, lung cancer, kidney failure, arthritis, COVID pneumoniaall could be reconceived as the results of cells, or systems of cells, functioning abnormally. And all could be perceived as loci of cellular therapies. In The Song of the Cell, Mukherjee tells the story of how scientists discovered cells, began to understand them, and are now using that knowledge to create new humans. He seduces you with writing so vivid, lucid, and suspenseful that complex science becomes thrilling. Told in six parts, laced with Mukherjee's own experience as a researcher, a doctor, and a prolific reader, The Song of the Cell is both panoramic and intimatea masterpiece.
Mutation is the engine that drives evolution and adaptation forward in that it generates the variation on which natural selection acts. Mutation is a random process that nevertheless occurs according ...to certain biases. Elucidating mutational biases and the way they vary across species and within genomes is crucial to understanding evolution and adaptation. Here we demonstrate that clonal pathogens that evolve under severely relaxed selection are uniquely suitable for studying mutational biases in bacteria. We estimate mutational patterns using sequence datasets from five such clonal pathogens belonging to four diverse bacterial clades that span most of the range of genomic nucleotide content. We demonstrate that across different types of sites and in all four clades mutation is consistently biased towards AT. This is true even in clades that have high genomic GC content. In all studied cases the mutational bias towards AT is primarily due to the high rate of C/G to T/A transitions. These results suggest that bacterial mutational biases are far less variable than previously thought. They further demonstrate that variation in nucleotide content cannot stem entirely from variation in mutational biases and that natural selection and/or a natural selection-like process such as biased gene conversion strongly affect nucleotide content.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Cell-fate specification is typically thought to precede and determine cell-cycle regulation during differentiation. Here we show that endoreplication, also known as endoreduplication, a specialized ...cell-cycle variant often associated with cell differentiation but also frequently occurring in malignant cells, plays a role in maintaining cell fate. For our study we have used Arabidopsis trichomes as a model system and have manipulated endoreplication levels via mutants of cell-cycle regulators and overexpression of cell-cycle inhibitors under a trichome-specific promoter. Strikingly, a reduction of endoreplication resulted in reduced trichome numbers and caused trichomes to lose their identity. Live observations of young Arabidopsis leaves revealed that dedifferentiating trichomes re-entered mitosis and were re-integrated into the epidermal pavement-cell layer, acquiring the typical characteristics of the surrounding epidermal cells. Conversely, when we promoted endoreplication in glabrous patterning mutants, trichome fate could be restored, demonstrating that endoreplication is an important determinant of cell identity. Our data lead to a new model of cell-fate control and tissue integrity during development by revealing a cell-fate quality control system at the tissue level.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Systems Biology Konieczny, Leszek; Roterman-Konieczna, Irena; Spólnik, Paweł
2023
eBook
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This open-access textbook is an excellent introduction to systems biology, which has developed rapidly in recent years. It discusses the processes in living organisms in an integrated way, enabling ...the reader to understand the fundamental principles and cause-effect relationships in biology and biochemistry. The authors have chosen an original but at the same time clear way of presenting the topics, repeatedly drawing comparisons and models from the macroscopic world and making the reader aware of the unity of the laws of physics, chemistry and biology. The fully updated 2nd edition also contains information that has only become available as a result of the increase in knowledge in recent years. This includes information on tumorigenesis, where significant progress has been made due to the explosive development of genetic knowledge as well as bioengineering with a highly effective technique adopted from the solutions of the bacterial world, such as CRISPR/CAS. This richly illustrated book is essential for postgraduate students and scientists of the following disciplines: biology, biotechnology, medicine, bioinformatics, robotics and automation, biocybernetics, and biomedical engineering. It is also an exciting read for anyone interested in biology.
Abstract Background Ischemia-reperfusion (IR) induces increased release of extracellular vesicles in the heart and exacerbates myocardial IR injury. We have previously shown that propofol attenuates ...hypoxia/reoxygenation (HR)-induced injury in human umbilical vein endothelial cells (HUVECs) and that microvesicles derived from propofol-treated HUVECs inhibit oxidative stress in endothelial cells. However, the role of microvesicles derived from propofol post-treated HUVECs ((HR + P)-EMVs) in IR-injured cardiomyocytes is unclear. In this study, we aimed to investigate the role of (HR + P)-EMVs in cardiac IR injury compared to microvesicles derived from hypoxic/reoxygenated HUVECs (HR-EMVs) and to elucidate the underlying mechanisms. Methods Hypoxia/reoxygenation (HR) models of HUVECs and AC16 cells and a mouse cardiac IR model were established. Microvesicles from HR-injured HUVECs, DMSO post-treated HUVECs and propofol post-treated HUVECs were extracted by ultra-high speed centrifugation, respectively. The above EMVs were co-cultured with HR-injured AC16 cells or injected intracardially into IR mice. Flow cytometry and immunofluorescence were used to determine the levels of oxidative stress and apoptosis in cardiomyocytes. Apoptosis related proteins were detected by Western blot. Echocardiography for cardiac function and Evans blue-TTC staining for myocardial infarct size. Expression of lncCCT4-2 in EMVs and AC16 cells was analysed by whole transcriptome sequencing of EMVs and RT-qPCR. The molecular mechanism of inhibition of myocardial injury by (HR + P)-EMVs was elucidated by lentiviral knockdown of lncCCT4-2, plasmid overexpression or knockdown of CCT4, and actinomycin D assay. Results In vitro and in vivo experiments confirmed that HR-EMVs exacerbated oxidative stress and apoptosis in IR-injured cardiomyocytes, leading to increased infarct size and worsened cardiac function. Notably, (HR + P)-EMVs induced significantly less oxidative stress and apoptosis in IR-injured cardiomyocytes compared to HR-EMVs. Mechanistically, RNA sequencing of EMVs and RT-qPCR showed that lncCCT4-2 was significantly upregulated in (HR + P)-EMVs and cardiomyocytes co-cultured with (HR + P)-EMVs. Reduction of lncCCT4-2 in (HR + P)-EMVs enhanced oxidative stress and apoptosis in IR-injured cardiomyocytes. Furthermore, the anti-apoptotic activity of lncCCT4-2 from (HR + P)-EMVs was achieved by increasing the stability of CCT4 mRNA and promoting the expression of CCT4 protein in cardiomyocytes. Conclusions Our study showed that (HR + P)-EMVs uptake by IR-injured cardiomyocytes upregulated lncCCT4-2 in cardiomyocytes and promoted CCT4 expression, thereby inhibiting HR-EMVs induced oxidative stress and apoptosis. Highlights Microvesicles from hypoxic/reoxygenated HUVECs (HR-EMVs) exacerbated oxidative stress and apoptosis in IR-injured cardiomyocytes. Microvesicles from propofol post-treated HUVECs ((HR + P)-EMVs) induced diminished oxidative stress and apoptosis in IR-injured cardiomyocytes compared with microvesicles from hypoxic/reoxygenated HUVECs (HR-EMVs). lncCCT4-2 was significantly highly expressed in (HR + P)-EMVs and cardiomyocytes co-cultured with (HR + P)-EMVs, and reduction of lncCCT4-2 in (HR + P)-EMVs enhanced oxidative stress and apoptosis in IR-injured cardiomyocytes. lncCCT4-2 inhibited HR-EMVs induced oxidative stress and apoptosis in HR-injured AC16 cells by increasing the stability of CCT4 mRNA and promoting the expression of CCT4 protein in AC16 cells.
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