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Topic Review
Cenancestor
Cenancestor, the last universal cellular ancestor (LUCA), is assumed to exist on the basis of extensive sharing of inferred homologous characters among representatives of living cellular organisms. These characters include the near universal genetic code, the concordance of phylogenetic trees from different genes, the sharing of fundamental biochemical processes and the existence of numerous transitional fossils. A cenancestor is a logical necessity if the cellular structure originated only once, given the cell theory stating that news cells are created by old cells dividing into two. The recent empirical search for the cenancestor started with the prediction that eukaryotes could not possibly have evolved from the common ancestor of extant bacterial species. This led to the discovery of Archaebacteria and the three domains of life. Archaebacteria was found to be "archae" only to eukaryotes and consequently renamed to Archaea. The molecular substantiation of the endosymbiotic hypothesis of mitochondrial and chloroplast origin led to the hypothesis that the nucleus in eukaryotes is also an organelle originating from endosymbiosis or cell fusion, followed by massive horizontal gene transfer (HGT) between an engulfing host and engulfed guests which serve as mitochondrial and chloroplast progenitors. The cenancestor is expected to coexist with a variety of viruses that may mediate HGT to bring heterogeneous genomes together. This virus-mediated and plasmid-mediated genomic assembly and exchange could abolish one major difficulty in creating endosymbiotic genomes, i.e., the need of primitive cells engulfing each other – a difficult feat if they had cell walls.
  • 354
  • 05 Sep 2023
Topic Review
Animal Model of Obesity Zucker Fatty Rats
Laboratory Zucker Fatty (ZF) rats are used in human disease studies as a model of obesity with accompanying hyperlipidemia and hypertension. While this model is most widely used in studies on genetic obesity, ZF rats are also used in studies on MetS and non-insulin-dependent obesity-related diabetes. ZF rats are characterized by a recessive mutation in the leptin receptor gene (called “fa”), which leads to polyphagia, with the consequent development of obesity at around four weeks of age. The causes of obesity in ZF rats also include hypertrophy and adipocyte hyperplasia, which are linked to their genetic predisposition. Other conditions observed in ZF rats include hyperinsulinemia and impaired glucose tolerance, which do not lead to overt diabetes.
  • 479
  • 05 Sep 2023
Topic Review
Avian Leukosis VIrus (ALV)
Avian leukosis viruses (ALVs) have been virtually eradicated from commercial poultry. However, some niches remain as pockets from which this group of viruses may reemerge and induce economic losses. Such is the case of fancy, hobby, backyard chickens and indigenous or native breeds, which are not as strictly inspected as commercial poultry and which have been found to harbor ALVs. In addition, relics of ancient infections by ALV remain in the genome of birds, with which ALV may recombine and generate new viruses.
  • 1.1K
  • 05 Sep 2023
Topic Review
Structure of Glycosylated Arsenicals
Microalgae are abundant components of the biosphere rich in low molecular weight carbohydrate-containing natural products (glycoconjugates). Glycoconjugates take part in the processes of photosynthesis, provide producers with important biological molecules, influence other organisms and are known by their biological activities. Some of them, for example, glycosylated toxins and arsenicals, are detrimental and can be transferred via food chains into higher organisms, including humans. 
  • 277
  • 05 Sep 2023
Topic Review
Control of Pseudomonas aeruginosa Virulence by One-Component Systems
Pseudomonas aeruginosa is a pathogen capable of colonizing virtually every human tissue. The host colonization competence and versatility of this pathogen are powered by a wide array of virulence factors necessary in different steps of the infection process. This includes factors involved in bacterial motility and attachment, biofilm formation, the production and secretion of extracellular invasive enzymes and exotoxins, the production of toxic secondary metabolites, and the acquisition of iron. Expression of these virulence factors during infection is tightly regulated, which allows their production only when they are needed. This process optimizes host colonization and virulence.
  • 269
  • 05 Sep 2023
Topic Review
Crosstalk between ILC3s and Microbiota
In recent years, growing evidence has suggested that the gut microbiome can significantly influence antitumor immunity, both within and outside the gastrointestinal tract, thereby affecting the efficacy of immune checkpoint inhibitors (ICIs). A link between microbiota composition and response to ICIs has been reported in both mouse and human studies. Gut microbial features depend on a delicate balance of tolerance for commensal microbiota and defense against various potentially pathogenic microbiota orchestrated by host immune system. Type 3 innate lymphoid cells (ILC3s) are a group of tissue-resident innate lymphocytes related to host immune cell–microbiome interactions. They orchestrate immunity, inflammation and tolerance in the intestines and any alterations in their functions can cause gut inflammation, colon cancer and immunotherapy resistance.
  • 228
  • 05 Sep 2023
Topic Review
Diopatra
The genus Diopatra is a major driver in sedimentary systems, altering the structure of habitats and changing the frequency of refugia and predator access to prey. It is taken as prey by a variety of shorebirds, crustaceans, and fish and used worldwide as bait.
  • 352
  • 05 Sep 2023
Topic Review
Enzymatic Cleavages
Human whole saliva is a hypotonic fluid lining the oral cavity and is composed of water (99%) and a complex mixture of organic and inorganic compounds resulting from salivary gland secretion, oral flora, the oropharynx, the upper airway, gastrointestinal reflux, gingival crevicular fluid, food deposits, and mucosal surface secretion containing blood-derived components. The most-common PTM detectable in human saliva is the proteolytic cleavage of proteins.
  • 233
  • 05 Sep 2023
Topic Review
Hypoxia's Influence on Bone Remodeling Molecular Pathways
Bone remodeling is a crucial physiological process for maintaining skeletal health. It focuses on the central roles of osteoblasts, osteoclasts, and osteocytes, as well as the composition of the bone's extracellular matrix. Furthermore, it explores the impact of hypoxia, or low oxygen levels, on bone health and elucidates the responsible molecular mechanisms. While bone remodeling units (BMUs), their cellular components, and the phases of the remodeling cycle remain not fully understood, the text also addresses systemic and local factors, including the critical RANK-RANKL-OPG pathway, that govern bone remodeling. This contributes to a comprehensive understanding of this intricate biological process.
  • 232
  • 04 Sep 2023
Topic Review
Exosomes and Microvesicles in Rheumatoid Arthritis Pathogenesis
Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease, characterized by persistent joint inflammation, leading to cartilage and bone destruction. Autoantibody production is directed to post-translational modified (PTM) proteins, i.e., citrullinated or carbamylated. Autophagy may be the common feature in several types of stress (smoking, joint injury, and infections) and may be involved in post-translational modifications (PTMs) in proteins and the generation of citrullinated and carbamylated peptides recognized by the immune system in RA patients, with a consequent breakage of tolerance. 
  • 188
  • 04 Sep 2023
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