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The Parasite's Way of Life
Published in Eric S. Loker, Bruce V. Hofkin, Parasitology, 2023
Eric S. Loker, Bruce V. Hofkin
The developmental changes that occur in all living things during their lives are especially noticeable in those organisms that use very different habitats at different points in their life cycle. Striking changes, for instance, in both body plan and physiology are typical of insects with aquatic larvae and terrestrial adults. Many parasites also undergo dramatic developmental changes as they move from one habitat or host to the next. We know a great deal about precisely what developmental changes transpire during a parasite’s life cycle. Although we know considerably less about how these changes occur, in recent years substantial progress has been made regarding the mechanisms underlying developmental change. Advances in fields such as transcriptomics have started to allow the identification of the environmental signals used by parasites to initiate developmental change, as well as how these signals are detected, transduced, and how they impact gene expression at various life cycle stages.
Caenorhabditis elegans in Computational Research
Published in Theodore B. Achacoso, William S. Yamamoto, AY's Neuroanatomy of C. elegans for Computation, 2022
Theodore B. Achacoso, William S. Yamamoto
Caenorhabditis elegans (Phylum Nematoda, Class Secernentea or Phasmidia, Order Rhabditida, and Family Rhabditidae) is an one millimeter, transparent, free-living soil nematode found commonly in many parts of the world. A mature worm lives for about 17 days after reaching adulthood. C. elegans follows the typical nematode body plan of two concentric tubes, separated by a space called the pseudocoelom. The inner tube is in the intestine, the intestine and the gonad are in the pseudocoelomic space, and the outer tube consists of the cuticle, hypodermis, neurons, and muscles. In a live worm, shape is maintained by internal hydrostatic pressure.
Amazing ambitions
Published in Brendan Curran, A Terrible Beauty is Born, 2020
‘Master genes’ which make sure that the basic structure of progeny is identical with that of the parents strictly control the processes underlying the formation of a body plan. The pattern of development from a fertilised egg is similar regardless of the species; what differs is the detail. In each case the fertilised egg divides into a ball of similar cells but soon they start to look and act differently from one another. Special proteins are produced by some cells and sent to others to ‘tell’ them which type of cell to become, signals which activate or switch off various genes in the target cells. The extremely subtle influences of these ‘master proteins’ ensure (in the case of humans, for example) that the cells divide and assemble properly to make the right number of foetal legs and arms in the correct place, that each hand has four fingers and a thumb and that these appendages are of equal length on both sides. A similar set of signals causes the ribs to form in pairs at the correct sites along the backbone and that the inner organs fit perfectly inside the body cavity. In the case of four-legged animals, the body architecture is different in that the forelimbs are legs rather than hands, but the basic principle is the same for all multi-cellular living things.
Stiffness estimation of transversely anisotropic materials using a novel indentation tester with a rectangular hole
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Atsutaka Tamura, Mika Saiki, Jun-ichi Hongu, Takeo Matsumoto
Gastrulation is an essential step in the development of most animals. This process is fundamental to vertebrate animals, and it is the early developmental stage in which a single layer of cells gives rise to multiple germ layers, enabling the differentiation of the internal tissues of the body (Gilbert 2014; Urry et al. 2016); in other words, the body plan of the animal embryo is shaped through the process of gastrulation. In mammals, a cascade of morphogenesis-related molecular events, e.g. polarization, intercalation, and intercellular adhesion, occurs in specific embryonic territories although knowledge about how the territories grow physically and remodel has remained elusive. Thus, characterization of the early developmental process during gastrulation is important to accurately describe the precise timing of cell-type specification.
Targeting transcription factors in multiple myeloma: evolving therapeutic strategies
Published in Expert Opinion on Investigational Drugs, 2019
Shirong Li, Sonia Vallet, Antonio Sacco, Aldo Roccaro, Suzanne Lentzsch, Klaus Podar
Transcription is the first step of gene expression by which genetic information is copied from DNA to RNA by RNA polymerases. RNA molecules include mRNA, which serves as a template for protein synthesis through translation; as well as non-coding RNAs, rRNA, tRNA, siRNAs, miRNAs, lncRNAs and ribozymes in particular. Transcriptional programs warrant cell identity, division, growth, death, migration, and thereby organization of the organism (body plan) throughout life; and intermittently in response to extracellular signals including hormones, cytokines and growth factors. Transcription factors (TFs) are proteins that bind to the DNA helix at specific sequences (response elements: promoters; enhancers; and clustered enhancers, so-called super-enhancers (SE)) and thereby prompt (as activators) or block (as repressors) the recruitment and activity of RNA polymerases [1,2].
Antifouling activity of portimine, select semisynthetic analogues, and other microalga-derived spirocyclic imines
Published in Biofouling, 2018
Darby G. Brooke, Gunnar Cervin, Olivier Champeau, D. Tim Harwood, Henrik Pavia, Andrew I. Selwood, Johan Svenson, Louis A. Tremblay, Patrick L. Cahill
Cyclic imines are generally fast-acting bioactives that inhibit neuromuscular transmission in mice via blockade of nicotinic acetylcholine receptors, leading to respiratory failure and death. Interestingly, the acute toxicity of 1 in mice via intraperitoneal injection (LD50 1,570 µg kg−1) is considerably less than that of 2 (LD50 96 µg kg−1), 3 (LD50 6.9 µg kg−1) and 4 (LD50 16 µg kg−1). Unlike the other cyclic imines, 1 also displays pro-apoptotic activity in cells (Cuddihy et al. 2016). Apoptosis plays a key role in the metamorphic processes of many biofouling organisms, being necessary for the complete body-plan restructuring that occurs as part of the transition from free-swimming larva to sessile juvenile (eg Chambon et al. 2002; Roccheri et al. 2004). It is therefore possible that this novel natural product is a defence against overgrowth by other organisms in the benthic environment.