Communicative and Integrative Biology最新文献

Quorum sensing (QS) is a critical bacterial communication system regulating behaviors like biofilm formation, virulence, and antibiotic resistance. This review highlights QS's role in polymicrobial infections, where bacterial species interactions enhance antibiotic resistance. We examine QS mechanisms, such as acyl-homoserine lactones (AHLs) in Gram-negative bacteria and autoinducing peptides (AIPs) in Gram-positive bacteria, and their impact on biofilm-associated antibiotic resistance. The challenges uniquely associated with polymicrobial infections, such as those found in cystic fibrosis lung infections, chronic wound infections, and medical device infections, are also summarized. Furthermore, we explore various laboratory models, including flow cells and dual-species culture models, used to study QS interactions in polymicrobial environments. The review also discusses promising quorum sensing inhibitors (QSIs), such as furanones and AHL analogs, which have demonstrated efficacy in reducing biofilm formation and virulence in laboratory and clinical studies. By addressing the interplay between QS and antibiotic resistance, this paper aims to advance therapeutic strategies that disrupt bacterial communication and improve antibiotic efficacy, ultimately mitigating the global challenge of antibiotic resistance in polymicrobial infections.

The bird of paradise plant is a clumping tropical species native to South Africa. It is a dramatic plant with distinctive iridescent orange and midnight blue flowers that resemble an exotic bird peeking out from the broad leaves in autumn, winter and spring. An experiment was conducted during the two seasons of 2021 and 2022 at a private farm in Damanhour, Beheira Governorate, Egypt (31"°" 04 "°"N, 30"°" 47' °E) to study the effect different concentrations of nano-potassium and chitosan and their combinations on the bird of Paradise (Sterlitiza reginae). The experiment was conducted in a randomized complete block in a split-plot design with five replicates; nano-potassium was used at 0, 100, 150, and 200 mg/l and assigned to the main plots, whereas the sub-plots involved 0, 0.25, 0.50 and 0.75 g/l of chitosan. An increase in plant height and leaf length was recorded when the plants were treated with 200 mg/l nano-potassium and 0.75 g/l chitosan. Spraying plants with concentrations of 150 mg/l nano-potassium and 0.75 g/l chitosan is associated with the superiority of S. reginae plants in other traits, such as leaves wide, number of leaves/plant, days to flowering, number of inflorescence/plant, number of florets/inflorescence, stalk length and diameter, inflorescence weight, longevity of inflorescence, and flowering period, compared to the other treatments. We conclude that adding nano-potassium and/or chitosan to the bird of paradise plant leads to an improvement in terms of vegetative and yield characteristics under newly reclaimed lands.

There is increasing evidence that exposure to weak electromagnetic fields (EMFs) generated by modern telecommunications or household appliances has physiological consequences, including reports of electromagnetic field hypersensitivity (EHS) leading to adverse health effects. Although symptoms can be serious, no underlying mechanism for EHS is known and there is no general cure or effective therapy. Here, we present the case study of a self-reported EHS patient whose symptoms include severe headaches, generalized fatigue, cardiac arrhythmia, attention and memory deficit, and generalized systemic pain within minutes of exposure to telecommunications (Wifi, cellular phones), high tension lines and electronic devices. Tests for cerebral, cardiovascular, and other physiological anomalies proved negative, as did serological tests for inflammation, allergies, infections, auto-immune conditions, and hormonal imbalance. However, further investigation revealed deficits in cellular anti-oxidants and increased radical scavenging enzymes, indicative of systemic oxidative stress. Significantly, there was a large increase in circulating antibodies for oxidized Low-Density Lipoprotein (LDLox), byproducts of oxidative stress accumulating in membranes of vascular cells. Because a known primary effect of EMF exposure is to increase the concentration of cellular oxidants, we propose that pathology in this patient may be causally related to a resulting increase in LDLox synthesis. This in turn could trigger an exaggerated auto-immune response consistent with EHS symptoms. This case report thereby provides a testable mechanistic framework for EHS pathology with therapeutic implications for this debilitating and poorly understood condition.

As every life form is composed of cells, elements of consciousness, namely memory and sentience, must be grounded in mechanisms that are integral to unicellular organisms. Earlier studies indicated that cellular cytoskeletal structures consisting of excitable, flexible, and oscillating polymers such as microtubules, along with quantum events, are potentially responsible for information processing and thus consciousness. This work attempts to solve the unknown, that is, how, at the spark of life, the phenomenon of cellular information processing first appears. This study posits that the spatially distributed wave energy of the molecules of an incepting cell interacts with space and generates a rotating bioinformation field, forming a vortex. This vortex, the local energy maximum, whose inbound and outbound energy fluxes represent signal reception and dispersal, is a critical step in the spark of life responsible for information storage, and with incremental wave superpositions, exhibits information processing. The vorticity of the rotating field is computed, and the obtained field characteristics indicated the emergence of a prebiotic complex to initiate information processing. Furthermore, the developed system model explains how perturbations from the environment are converted into response signals for the emanation of sense, locomotion, nutrition, and asexual reproduction, the fundamental evolutionary building blocks of prokaryotes. Further research directions include explaining how the energy potential available in the bio-information field and the vortex leads to the first formation of genetic material, emergence of cytoskeleton, and extension of bio-information field to multi-cellular organisms.

Сoding sequences of seven housekeeping genes: actin SaACT7, ubiquitin-conjugating protein SaUBC10, glyceraldehyde-3-phosphate dehydrogenase SaGAPDH, protein of the large subunit of ribosomes SaL2, α-tubulin SaTUA, translation elongation factor SaeEF1α, and protein phosphatase SaPP2A were identified as candidate reference genes for expression analysis of target genes in the extremely salt tolerant plant Suaeda altissima (L.) Pall. The expression profiles of the genes differed. SaACT7 and SaeEF1α demonstrated the highest expression levels, while the lowest expression levels were found for SaPP2A and SaTUA. SaPP2A and SaeEF1α genes were the most stably expressed at different steady-state salinity levels and different nitrate concentrations in nutrient solutions (NSs). SaL2, SaPP2A, and SaeEF1α genes showed the greatest stability of expression when nitrate was added to nutrient solution of plants grown under conditions of nitrate deficiency. Less constant expression was demonstrated in this experiment by SaACT7 and SaTUA. SaL2, SaACT7, SaeEF1α, and SaUBC10 genes showed the smallest expression changes under salt shock. To validate the use of the most stably expressed genes for normalization of gene expression, we checked them as reference genes to study the expression of the nitrate transporter gene SaNPF6.3 in S. altissima roots under conditions of different salinity and different nitrate supply.

The Dead Sea is unique compared to other extreme halophilic habitats. Its salinity exceeds 34%, and it is getting saltier. The Dead Sea environment is characterized by a dominance of divalent cations, with magnesium chloride (MgCl₂) levels approaching the predicted 2.3 M upper limit for life, an acidic pH of 6.0, and high levels of absorbed ultraviolet radiation. Consequently, only organisms adapted to such a polyextreme environment can survive in the surface, sinkholes, sediments, muds, and underwater springs of the Dead Sea. Metagenomic sequence analysis and amino acid profiling indicated that the Dead Sea is predominantly composed of halophiles that have various adaptation mechanisms and produce metabolites that can be utilized for biotechnological purposes. A variety of products have been obtained from halophilic microorganisms isolated from the Dead Sea, such as antimicrobials, bioplastics, biofuels, extremozymes, retinal proteins, colored pigments, exopolysaccharides, and compatible solutes. These resources find applications in agriculture, food, biofuel production, industry, and bioremediation for the detoxification of wastewater and soil. Utilizing halophiles as a bioprocessing platform offers advantages such as reduced energy consumption, decreased freshwater demand, minimized capital investment, and continuous production.

Biological theory assumes the organized appearance of life and the reliable recurrence of traits are due to inheritance. Natural selection acting on blind variations produces phenotypes with heritable traits, one of which may be natural learning. The aim of learning, then, is solving problems related to survival and reproduction. But what if these views confuse cause with effect? Perhaps a learning algorithm is required for any phenotype at all to arise. If so, evolution proceeds learning-first, with individuals pursuing another telos entirely. I argue that this aim may be epistemological, the drive to understand the world through an umwelt. By "understand" I mean neither association nor prediction but Karl Popper's concept of explanation through conjecture and refutation. I propose that if only genetic materials are truly heritable, not traits, then testing a successful physical theory of life will depend on building abiotic machines which can perform natural learning without the presence of any inherited materials or conditions. I name this process "epistolution," combining "epistemology" and "evolution," to distinguish it from other concepts. Epistolution is an integral consequence of any learning-first view of life, such as the Cellular Basis of Consciousness theory. This type of theory suggests that in all cells during the history of life full-blown agency, involving beliefs, intentions, and desires, generated all the phenotypes that have then been winnowed by natural selection. Unlike in other versions, I posit that the aim of agential living systems is the explanation of reality rather than inductive prediction or survival/reproduction.

In navigating to a better location, mobile organisms in diverse taxa change directions of travel occasionally, including bacteria, archaea, single-celled eukaryotes, and small nematode worms such as Caenorhabditis elegans. In perhaps the most common form of goal-orientated movement, the rate of such turns is adjusted in all these taxa to ascend (or descend) a chemical gradient. Basically, the rate of turns is reduced when the movement results in better conditions. In the bacterium Escherichia coli and in C. elegans, the turns are generated by random-rate processes, in which the probability of a turn occurring is constant at every moment. This is evidenced by a distribution of inter-turn intervals that has an exponential distribution. For the first time, we examined the distribution of inter-turn intervals in the single-celled eukaryote, Paramecium caudatum, in a class exercise for first-year university students. We found clear evidence for an exponential distribution of inter-turn intervals, implying a random-rate process in generating turns in Paramecium. The exercise also shows that university laboratory classes can be used to generate scientific data to address research questions whose answers are as yet unknown.

Two methods have been compared for determining the value of natural selection in the natural populations. The first method, based on the F_ST-statistics, employs the dependence of genetic diversity of a species on the value of gene flow between subpopulations of the species, derived from the assumption that all the mutations are close to selective neutrality, and subpopulations effect each other equally. Susceptibility to selection is estimated by the degree of deviation from this relationship between genetic diversity and gene flow in certain species. The second method is based on the probability theory and involves comparison between stabilities of the forms, competing in the population, which is computed using the data about fluctuations in their occurrence in several generations. As applied to the problems of genetic monitoring of rare and valuable species, the first method can be employed for express-assessment of susceptibility of a species to rapid intraspecific changes. The second method is suitable for a long-term and in-depth genetic monitoring of the species subjected to extremely intense natural selection of a disruptive or stabilizing form, which were revealed using the first method. There is a lack of long-term observations of intraspecific genetic variation of rare and protected species. The need for funds that finance long-term genetic research is substantiated.

Abiotic stress that plants face may impact their growth and limit their productivity. In response to abiotic stress, several endogenous survival mechanisms get activated, including the synthesis of quaternary amines in plants. Acetylcholine (ACh), a well-known quaternary amine, and its components associated with cholinergic signaling are known to contribute to a variety of physiological functions. However, their role under abiotic stress is not well documented. Even after several studies, there is a lack of a comprehensive understanding of how cholinergic components mitigate abiotic stress in plants. Acetylcholine hydrolyzing enzyme acetylcholinesterase (AChE) belongs to the GDSL lipase/acylhydrolase protein family and has been found in several plant species. Several studies have demonstrated that GDSL members are involved in growth, development, and abiotic stress. This review summarizes all the possible mitigating effects of the ACh-AChE system on abiotic stress tolerance and will try to highlight all the progress made so far in this field.