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  • Research Highlights: Lethal virus isolated from Sonoran tiger salamanders


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    By Glenn Bartolotti – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39112632

    Lethal virus isolated from Sonoran tiger salamanders

    • The Sonoran tiger salamander is a genetically distinct type of salamander confined to about 30 small ponds in a valley in southern Arizona, United States.
    • The Sonora tiger salamander is among the animals on the USA Federal List of Endangered Species.
    • These salamanders occasionally experience a disease outbreak that can wipe out a large portion of their population.
    • Researchers isolated a virus from these salamanders using fish cell cultures.
    • Researchers utilized an electron microscope and found that thin sections from the salamanders had a large quantity of enveloped and non-enveloped icosahedral virus particles.
    • The viral particles were about 170 nanometers in diameter and were found to be in the cytoplasm of skin and liver cells.
    • Researchers speculated that the virus was an iridovirus by analyzing the morphology and host pathology.
    • Iridovirus is a nuclear, cytoplasmic, large DNA-containing virus that can infect either an invertebrate like insects or cold-blooded vertebrates like reptiles and amphibians.[1]
    • Researchers concluded that the virus was the primary pathogen in these outbreaks.
    • Researchers named the virus Arabystoma tigrinum virus or ATV.
    • Although bacteria that can rupture red blood cells were isolated from sick salamanders, researchers failed to trigger the disease by exposing salamanders to these bacteria.

    Sources:

    Jancovich, J.K. et al. (1997). Isolation of a lethal virus from the endangered tiger salamander Ambystoma tigrinum stebbinsi. Diseases of Aquatic Organisms. https://asu.pure.elsevier.com/en/publications/isolation-of-a-lethal-virus-from-the-endangered-tiger-salamander-

    [1] V.G. Chinchar, A.D. Hyatt (2008). Encyclopedia of Virology (Third Edition)

  • Research Highlights: Warmer temperature increases metabolic processes and cell division but lowers protein synthesis in soil microbes


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    Image by Jose Antonio Alba from Pixabay

    Warmer temperature increases metabolic processes and cell division but lowers protein synthesis in soil microbes

    • Responses of soil microbes to global warming are important to conclude future soil-climate feedback; however, it is not well understood.
    • Researchers investigated microbial physiological responses to medium-term and long-term subarctic grassland soil warming of +6°C.
    • Medium-term is 8 years and long-term is more than 50 years.
    • Researchers observed indications for a community-wide increase in central metabolic pathways and cellular replication.
    • Additionally, researchers observed a reduction of bacterial protein biosynthesis machinery in the elevated temperature soils which occur at the same time with lower microbial biomass, RNA, and substrate content.
    • Researchers concluded that the increased reaction rates at higher temperatures and the reduction of substrates triggered ribosome reduction.
    • The ribosome is a macromolecular complex that carries protein synthesis.
    • Another study involving short-term warming experiment of +6°C at 6 weeks further supported the conclusion.
    • The reduction of protein biosynthesis machinery frees up energy and matter which allows soil microbes to continue a high metabolic process and cellular division even after years of increasing temperature.

    Source:

    Söllinger, A., et al. (2022). Down-regulation of the bacterial protein biosynthesis machinery in response to weeks, years, and decades of soil warming. Science Advances. https://www.science.org/doi/10.1126/sciadv.abm3230

  • Research Highlights: Microplastics detected in human blood


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    Microplastics detected in human blood

    • Plastic particles are common substances in the environment and food chain that cause pollution.
    • However, little is known about the exposure of plastic particles in human blood.
    • Researchers aimed to develop a strong and sensitive experimental method in order to measure plastic particles greater than 700 nanometers in human blood from 22 healthy participants.
    • Researchers discovered four polymers used in plastic production from human blood.
    • Polyethylene terephthalate, polyethylene and polymers of styrene, polymethyl-methacrylate, and polypropylene were all detected from the blood.
    • Polyethylene terephthalate is a common polymer resin of the polyester family and is utilized in fabrics, liquid and food containers, and thermoforming.[1]
    • Polymethyl-methacrylate is a transparent and rigid plastic often used to substitute glass such as shatterproof, skylights, and illuminated signs.[2]
    • Styrene is commonly used to make plastics and rubber for insulation, pipes, vehicle parts, printer cartridges, food containers, and carpet backing.[3]
    • Three of the polymers were quantified; however, polypropylene had a value so small that it could not be quantified.
    • The mean of the sum quantifiable concentration of plastic particles was 1.6 µg/ml.
    • The result shows the first measurement of the mass concentration of plastic polymers in human blood.
    • The study highlights the bioavailability of plastic particles for uptake into the human circulatory system.
    • Future study is needed to understand plastic particle exposure in humans and the related health hazard.

    Sources:

    Leslie, H.A., et al. (2022). Discovery and quantification of plastic particle pollution in human blood, Environment International. https://doi.org/10.1016/j.envint.2022.107199

    [1] De Vos, Lobke; Van de Voorde, Babs; Van Daele, Lenny; Dubruel, Peter; Van Vlierberghe, Sandra (December 2021). “Poly(alkylene terephthalate)s: From current developments in synthetic strategies towards applications”. European Polymer Journal. 161: 110840. https://doi.org/10.1016/j.eurpolymj.2021.110840

    [2] https://www.britannica.com/science/polymethyl-methacrylate

    [3] https://www.niehs.nih.gov/health/topics/agents/styrene/index.cfm

  • Research Highlights: Bacteria “vaccinate” themselves to protect from viral infection


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    Illustration CC BY-SA 4.0 Guido Hegasy

    Bacteria “vaccinate” themselves to protect from viral infection

    • Prokaryotes have developed various defense mechanisms against viruses.
    • CRISPR is one of the processes that protect prokaryotic organisms from viruses.
    • CRISPR allows bacteria to remember DNA from invading viruses and chop off viral DNA to stop the infection.
    • Researchers studied the relationship between two of the popular prokaryotic immune systems namely CRISPR and restriction-modification.
    • Both mechanisms utilize enzymes that cut a specific DNA sequence of the invading virus; however, CRISPR nucleases are programmed with phage-derived spacer sequences which are integrated into the CRISPR genetic position upon infection.
    • Researchers found restriction enzymes help in providing short-term defense which can be quickly overcome through methylation of the viral genome.
    • Methylation is a process by which a methyl group is added to DNA and inhibits gene expression.
    • Restriction enzymes can cut short DNA sequences so bacteria can utilize these DNA sequences soon after viral infection starts.
    • However, few other cells acquired spacer sequences from the cleavage site which moderate a strong type II-A CRISPR-Cas immune mechanism against the methylated virus.
    • This mechanism reminds us of the eukaryotic immune response in which the innate immunity provides a first short-term line of defense and also activates a second but stronger adaptive immune response.

    Sources:

    Maguin, P., Varble, A., Modell, J. W., & Marraffini, L. A. (2022). Cleavage of viral DNA by restriction endonucleases stimulates the type II CRISPR-Cas immune response. Molecular cell, 82(5), 907–919.e7. https://doi.org/10.1016/j.molcel.2022.01.012

  • Research Highlights: Microbes work together to form drug-tolerant communities


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    Image by WikiImages from Pixabay

    Microbes work together to form drug-tolerant communities

    • Microbial communities comprise cells with different metabolic capacities and may include auxotrophs.
    • Auxotroph is an organism, usually a mutant bacteria, that cannot synthesize substances needed for its growth and metabolism.[1]
    • Researchers analyzed amino acid biosynthesis pathways in auxotroph from microbiome data of more than 12,000 natural microbial communities.
    • Researchers also examined the auxotrophic-prototrophic interactions in yeast communities.
    • Researchers discovered a mechanism that links auxotrophs to an increase in metabolic interactions and anti-microbial drug tolerance.
    • The auxotrophs have been observed to obtain altered metabolic flux distribution, export more metabolites, and as a result, enrich the community in metabolites.
    • Metabolites are intermediate or end-product substances produced by metabolism.
    • These capabilities observed from auxotrophs may be the consequence of the metabolic adaptations required to use specific metabolites.
    • Additionally, researchers observed that the increased metabolite exportation was correlated with the decrease in intracellular drug concentrations.
    • The reduction of intracellular drug concentration allows microbes to grow even at drug levels above minimal inhibitory concentrations.
    • Minimal inhibitory concentration is the lowest concentration of drugs that can inhibit the growth of bacteria.[2]
    • Researchers demonstrated that an antifungal compound called azoles did not significantly eliminate yeast cells that use metabolites from a metabolically-enriched environment.
    • The results describe a mechanism that enhances our understanding of why cells are more tolerant to drug exposure when they metabolically interact.

    Sources:

    Yu, J.S.L., Correia-Melo, C., Zorrilla, F. et al. Microbial communities form rich extracellular metabolomes that foster metabolic interactions and promote drug tolerance. Nat Microbiol (2022). https://doi.org/10.1038/s41564-022-01072-5

    [1] https://www.thefreedictionary.com/auxotroph

    [2] https://en.wikipedia.org/wiki/Minimum_inhibitory_concentration

  • Research Highlights: Blind cavefishes have larger red blood cells to survive in a low-oxygen habitat


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    By H. Zell – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=15270315

    Blind cavefishes have larger red blood cells to survive in a low-oxygen habitat

    • Animals that thrive in extreme environments can be used to study adaptive evolution in response to different pressures.
    • One example of these pressures is reduced oxygen levels.
    • Environments with low oxygen are commonly found in subterranean and high-altitude regions.
    • Animals living in caves must also deal with starvation and the dark environment, both of which have been thoroughly studied as an important factor driving the evolution of traits related to caves.
    • Hypoxia, the state in which oxygen is lacking at the tissue level, does not receive much attention as an environmental pressure.
    • Researchers examined adaptive characteristics evolving in Mexican tetra, also known as the blind cavefish.
    • Mexican tetra is notable for having no eyes or pigment.[1]
    • Mexican tetra has two forms, surface-dwelling, and cave-dwelling.
    • Additionally, researchers also identified other responses to hypoxia with the help of many natural and independently-colonized cave populations together with closely-related surface animals of the same species.
    • Researchers focused on a very important oxygen-carrier molecule called hemoglobin.
    • Researchers discovered that numerous cave populations had higher hemoglobin concentration which was proportional to the increase in red blood cell size of the cave-dwelling form compared to the surface-dwelling fish.
    • Interestingly, both cave and surface-dwelling fishes had similar concentrations of red blood cells which suggest that higher hemoglobin levels were not due to the rise of red blood cell count.
    • Researchers speculated that the larger-sized red blood cells in cavefish contain more hemoglobin.
    • The study reinforces the idea that cavefish have adapted to low oxygen environments through changes in both red blood cell size and hemoglobin production.

    Sources:

    Boggs, T.E., Friedman, J.S. & Gross, J.B. Alterations to cavefish red blood cells provide evidence of adaptation to reduced subterranean oxygen. Sci Rep 123735 (2022). https://doi.org/10.1038/s41598-022-07619-0

    [1]  Keene, A.; Yoshizawa, M.; McGaugh, S. (2016). Biology and Evolution of the Mexican Cavefish. pp. 68–69, 77–87. ISBN978-0-12-802148-4

  • Research Highlights: Brandt’s voles cut grass to monitor predators


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    By Bogomolov.PL – Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=7038188

    Brandt’s voles cut grass to monitor predators

    • The interactions between predators and preys are common and can significantly affect the structure of ecological communities.
    • Habitat complexity has been shown to have importance in the regulation of predator-prey interaction strength.
    • Habitat complexity refers to the level or strength of interaction between a species and its environment.[1]
    • Changes in the structure of habitat can affect the efficacy of both predatory and anti-predatory behaviors.
    • Some prey species conduct engineering activities that modify the environment to reduce being hunted.
    • However, the consequences of these engineering activities are still not fully understood.
    • Researchers evaluated how changes in habitat by Brandt’s voles affects predation risk from shrike in grassland.
    • Researchers discovered that voles change the structure of habitat by cutting down large bunch grass when shrike are present.
    • The grass-cutting behavior of these voles dramatically reduced the number of unpalatable grasses which results in the reduction of shrike visitation.
    • The results show that modifying habitat structure can reduce predation risk in certain herbivorous prey.
    • The relationship between predation risk and ecosystem engineering may be important; however, it is not a valued mechanism at play in the natural world.

    Sources:

    Zhong, Z. et. al. (2022). A rodent herbivore reduces its predation risk through ecosystem engineering, Current BiologyDOI: 10.1016/j.cub.2022.02.074

    [1] https://link.springer.com/referenceworkentry/10.1007/978-94-017-8801-4_234

  • Research Highlights: Scientists provide new clues on how our hair has evolved


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    photo of lemur
    Photo by Magda Ehlers on Pexels.com

    Scientists provide new clues on how our hair has evolved

    • Hair is one of the most important features in primates which include humans.
    • Some functions of the hair are associated with thermoregulation, camouflage, protection, and signaling.
    • However, the evolution of the wild primate pelage is still not well understood.
    • Pelage is the covering of mammals consisting of hair, fur, or wool.[1]
    • Researchers examined whole body hair color and density variation in lemurs.
    • Lemurs are wet-nosed mammals with pointy snouts, long tails, and large eyes, and can only be found in Madagascar.
    • Lemurs exhibit vertical posture like humans and their bodies are vertical to the sun.
    • Researchers obtained hair color and density from museum and wild animals.
    • They also obtain opsin genotypes from wild animals and obtain climate data from WorldClim.
    • Opsin is a protein that binds to light-reactive chemicals associated with vision, phototaxis, and circadian rhythms.[2]
    • Researchers discovered that across the Indriidae family, lemurs with darker hair can be found in wet regions.
    • However, one of the genus called Sifaka, dark black hair is commonly found in cold forest regions.
    • Additionally, the red pelage population is positively correlated with enhanced color vision.
    • Researchers also found the follicle density on lemur’s crown and limbs increases in dry and open environments.
    • The study highlights the effect of selective pressures on primate hair evolution.
    • The study provides one-of-a-kind empirical evidence that supports an early hypothesis regarding the hair evolution of hominin.

    Sources:

    Tapanes, E. et al. (2022). Hair phenotype diversity across Indriidae lemurs, American Journal of Biological AnthropologyDOI: 10.1002/ajpa.24508

    [1] https://www.thefreedictionary.com/pelage

    [2] https://www.sciencedirect.com/topics/neuroscience/opsin

  • Research Highlights: New species of cephalopod with ten arms discovered in Montana


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    New species of cephalopod with ten arms discovered in Montana

    • Vampyropods are soft-bodied cephalopods that have eight arms and an internalized chitinous shell.[1]
    • Researchers discovered an exceptionally well-preserved vampyropod from the Carboniferous Bear Gulch Lagerstätte of Montana in the United States.
    • The newly discovered vampyropod was named Syllipsimopodi bideni gen. et sp. nov.
    • The specimen has an internalized shell and ten arms with suckers arranged in two rows.
    • It is the only known vampyropod to retain the ten arms from its ancestor.
    • Syllipsimopodi is the oldest conclusive vampyropod and crown coleoid which pushes back this animal group’s fossil record by about 82 million years.
    • Researchers showed that Syllipsimopodi is the earliest-diverging known vampyropod.
    • This idea disputes the common hypothesis that vampyropods descended from Phragmoteuthid belemnoid of the Triassic period.
    • As early as the Mississippian, vampyropods were characterized by the loss of the chambered phragmocone and primordial rostrum.
    • Phragmocone is the chambered portion of the cephalopod’s shell.
    • Evidence suggests that the specimen may have elongated arms which when combined with certain structures such as the terminal fins, shows that the earliest vampyropods appeared to be similar to extant squids.

    Sources:

    Whalen, C.D., Landman, N.H. Fossil coleoid cephalopod from the Mississippian Bear Gulch Lagerstätte sheds light on early vampyropod evolution. Nat Commun 13, 1107 (2022). https://doi.org/10.1038/s41467-022-28333-5

    [1] American Museum of Natural History. (2022, March 8). New species of extinct vampire-squid-like cephalopod is the first of its kind with 10 functional arms: Description of exceptionally preserved fossil pushes back age of Vampyropoda by nearly 82 million years. ScienceDaily. Retrieved March 8, 2022 from www.sciencedaily.com/releases/2022/03/220308115650.htm

  • Research Highlights: Hibernation can prolong life in yellow-bellied marmot


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    By Diliff – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=26414860

    Hibernation can prolong life in yellow-bellied marmot

    • Animals that hibernate can live longer than would be expected based on their body size.
    • Hibernation is a process by which metabolic activities are suppressed, also called torpor, for long periods and interspersed by short periods of increased metabolism or arousal.
    • During hibernation, the torpor-arousal cycle occurs multiple times and it has been speculated that processes regulating the torpor-arousal transition cause aging to halt.
    • There is a relationship between metabolic rate and long life; thus, researchers proposed the hibernation-aging hypothesis which states that aging is temporarily halted during hibernation.
    • Researchers tested the hibernation-aging hypothesis in a well-studied population of yellow-bellied marmots.
    • Yellow-bellied marmot is a large, stout-bodied ground squirrel and also known as the rock chuck [1]
    • Yellow-bellied marmot can hibernate for up to 8 months per year.
    • Researchers estimated the epigenetic age of these marmots.
    • The result showed a logarithmic curve of epigenetic age with time.
    • Initially, epigenetic age increased at a higher rate until the female marmots reached about 2 years old.
    • At the age of 2 years, the anti-aging phenomenon begins.
    • Epigenetic age increased during the active season while hindered during hibernation.
    • Overall, the results described the hibernation-aging hypothesis and may explain the longer lives in yellow-bellied marmots.

    Sources:

    Pinho, G.M., Martin, J.G.A., Farrell, C. et al. Hibernation slows epigenetic ageing in yellow-bellied marmots. Nat Ecol Evol (2022). https://doi.org/10.1038/s41559-022-01679-1

    [1] Thorington, R.W., Jr.; Hoffman, R.S. (2005). “Family Sciuridae”. In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 801. ISBN978-0-8018-8221-0OCLC62265494