ARTICLE | doi:10.20944/preprints201903.0213.v4
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: compensatory habitat, frog, invertebrate, predation, reintroduction, tadpoles
Online: 2 April 2019 (15:25:57 CEST)
The role of invertebrate predation in shaping vertebrate communities is often underestimated or overlooked, which has resulted in the lack of their recognition in conservation planning. This is evident with predaceous diving beetles (Coleoptera: Dytiscidae) which are often the top predator in many aquatic freshwater habitats. During weekly monitoring of a compensatory habitat reintroduction for an endangered frog species, a group of a dozen adult diving beetles were encountered attacking and quickly dismembering and consuming a tadpole. A single adult diving beetle was also discovered burrowing its head deep inside and consuming a tadpole approximately three to four times its size. Although Dytiscidae are known to occasionally consume vertebrates such as tadpoles, adults are typically considered scavengers, and this communal predatory behavior and feeding method have not been previously documented. Besides these interesting novel behaviors, these observations may have implications for amphibian conservation since management efforts are not typically concerned with naturally occurring ubiquitous threats such as those from small invertebrate predators, as it is rarely been observed in nature. However, this may be perhaps due to their ability to consume prey rapidly, especially if predating in groups. Although amphibian conservation plans expect some losses from natural predation, diving beetles may affect conservation efforts such as captive breeding and reintroductions with populations already on the threshold of extinction and where every individual critical to success.
REVIEW | doi:10.20944/preprints202109.0028.v1
Subject: Biology And Life Sciences, Toxicology Keywords: toxicity; effect; fish; invertebrate; mussels
Online: 1 September 2021 (15:52:02 CEST)
Glyphosate (N-(phosphonomethyl)glycine) is a herbicide used to kill broadleaf weeds and grass, developed in the early 1970s. The widely occurring degradation product aminomethylphosphonic acid (AMPA) is a result of glyphosate and amino-polyphosphonate degradation. The massive use of the parent compounds leads to the ubiquity of AMPA in the environment, and particularly in water. Considering this, it can be assumed that glyphosate and its major metabolites could pose a potential risk to aquatic organisms. This review summarises current knowledge about residual glyphosate and their major metabolite AMPA in the aquatic environment, including status and toxic effects in aquatic organisms, mainly fish, are reviewed. Based on the above, we identify major gaps in the current knowledge and some directions for future research knowledge about the effects of worldwide use of herbicide glyphosate and its major metabolite AMPA. The toxic effect of glyphosate and their major metabolite AMPA has mainly influenced growth, early development, oxidative stress biomarkers, antioxidant enzymes, haematological, biochemical plasma indices, caused histopathological changes in the aquatic organism.
REVIEW | doi:10.20944/preprints201807.0260.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: mitochondria; invertebrate; reactive oxygen species; oxidative phosphorylation
Online: 16 July 2018 (08:27:03 CEST)
Neurodegenerative diseases like Alzheimer’s disease (AD) are poised to become a global health crisis, and therefore understanding the mechanisms underlying the pathogenesis is critical for the development of therapeutic strategies. Mutations in genes encoding presenilin occur in most familial Alzheimer’s disease but the role of PSEN in AD is not fully understood. In this review, the potential modes of pathogenesis of AD are discussed, focusing on calcium homeostasis and mitochondrial function. Moreover, research using Caenorhabditis elegans to explore the effects of calcium dysregulation due to presenilin mutations on mitochondrial function, oxidative stress and neurodegeneration is explored.
REVIEW | doi:10.20944/preprints202102.0030.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: AEA; 2-AG; CB1; CB2; endocannabinoid; regeneration; neurodevelopment; invertebrate
Online: 1 February 2021 (13:16:51 CET)
Cannabis has long been used for its medicinal and psychoactive properties. With the relatively new adoption of formal medicinal cannabis regulations worldwide, the study of cannabinoids, both endogenous and exogenous, has similarly flourished in more recent decades. In particular, research investigating the role of cannabinoids in regeneration and neurodevelopment has yielded promising results in vertebrate models. However, regeneration-competent vertebrates are few, whereas a myriad of invertebrate species have been established as superb models for regeneration. As such, this review aims to provide a comprehensive summary of the endocannabinoid system, with a focus on current advances in the area of endocannabinoid system contributions to invertebrate neurodevelopment and regeneration.
REVIEW | doi:10.20944/preprints201908.0112.v1
Subject: Social Sciences, Behavior Sciences Keywords: active sensing; navigation; neural circuits; inhibition; C. elegans; invertebrate
Online: 8 August 2019 (17:24:40 CEST)
From single-cell organisms to complex neural networks, all evolved to provide control solutions to generate context and goal-specific actions. Neural circuits performing sensorimotor computation to drive navigation employ inhibitory control as a gating mechanism, as they hierarchically transform (multi)sensory information into motor actions. Here, we focus on this literature to critically discuss the proposition that prominent inhibitory projections form sensorimotor circuits. After reviewing the neural circuits of navigation across various invertebrate species, we argue that with increased neural circuit complexity and the emergence of parallel computations inhibitory circuits acquire new functions. The contribution of inhibitory neurotransmission for navigation goes beyond shaping the communication that drives motor neurons, instead, include encoding of emergent sensorimotor representations. A mechanistic understanding of the neural circuits performing sensorimotor computations in invertebrates will unravel the minimum circuit requirements driving adaptive navigation.
ARTICLE | doi:10.20944/preprints202105.0684.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Paracentrotus lividus; Transformers; Trf; 185/333; invertebrate immunity; phagocytosis; model organism
Online: 27 May 2021 (15:09:05 CEST)
Sea urchins are long-living invertebrates with a complex immune system which includes extended families of immune receptors. A central immune gene family in the sea urchins encodes for the Transformer (Trf) proteins. The Trf family was so far studied mainly in the purple sea urchin Strongylocentrotus purpuratus. In this study, we explored this protein family in the Mediterranean Sea urchin Paracentrotus lividus. The PlTrf genes and predicted proteins were found to be highly diverse and showed a typical Trf size range and structure. We found that P. lividus coelomocytes and hemolymph contain different PlTrf protein repertoires with a shared subset which specifically bind E. coli bacteria. Using FACS, we identified five different P. lividus coelomocyte sub-populations with cell surface Trf protein expression. The relative abundance of the Trf-positive cells sharply increased following immune challenge with E. coli bacteria, but not following challenge with LPS or sea urchin pathogen V. penaeicida. Finally, we demonstrated that the phagocytosis of E. coli bacteria by P. lividus phagocytes is mediated through the hemolymph and is inhibited by blocking Trf activity with anti-Trf antibodies. Together, our results suggest collaboration between cellular and humoral Trf-mediated effector arms in the P. lividus specific immune response to pathogens.
ARTICLE | doi:10.20944/preprints202002.0321.v1
Subject: Biology And Life Sciences, Virology Keywords: honey bee; deformed wing virus; RNA virus vector; invertebrate virus; virus evolution; pollination; food security
Online: 23 February 2020 (12:15:14 CET)
We developed a honey bee RNA-virus vector based on the genome of a picorna-like Deformed wing virus (DWV), the main viral pathogen of the honey bee (Apis mellifera). To test the potential of DWV to be utilized as a vector, the 717 nt sequence coding for the enhanced green fluorescent protein (eGFP), flanked by the peptides targeted by viral protease, was inserted into an infectious cDNA clone of DWV in-frame between the leader protein and the virus structural protein VP2 genes. The in vitro RNA transcripts from egfp-tagged DWV cDNA clones were infectious when injected into honey bee pupae. Stable DWV particles containing genomic RNA of the recovered DWV with egfp inserts were produced, as evidenced by cesium chloride density gradient centrifugation. These particles were infectious to honey bee pupae when injected intra-abdominally. Fluorescent microscopy showed GFP expression in the infected cells and Western blot analysis demonstrated accumulation of free eGFP rather than its fusions with DWV LP and/or VP2 proteins. Analysis of the progeny egfp-tagged DWV showed gradual accumulation of genome deletions for egfp, providing estimates for the rate of loss of a non-essential gene an insect RNA virus genome during natural infection.
ARTICLE | doi:10.20944/preprints201811.0264.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: feeding behavior; Peripatidae; invertebrate behavior; undescribed Costa Rican onychophorans; parental investment
Online: 12 November 2018 (04:51:33 CET)
We report, for the first time in onychophorans, food hiding, parental feeding investment and an ontogenetic diet shift, from adhesive to prey, after their first two weeks of life.
ARTICLE | doi:10.20944/preprints202310.1188.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: invertebrate welfare; Octopus vulgaris; Anaesthetic protocol; Isoflurane; Magnesium chloride; stress reduction
Online: 19 October 2023 (03:28:44 CEST)
A wide variety of substances have been used to anaesthetise invertebrates, but many are not anaesthetics and merely incapacitate animals, rather than preventing pain. Much is now known about the mode of action of modern clinical and veterinary anaesthetics because of their use on human beings and other vertebrates. In essence, the role of an ideal general anaesthetic is to act as a muscle relaxant, an analgesic, an anaesthetic and an amnesic. To achieve all these properties with a single substance is difficult and various adjuvants usually need to be administered, resulting in a cocktail of drugs. In a clinical setting, the vast majority of patients are unaware of surgery being carried out and have no memory of it, so they can claim to have felt no pain, but this is much more difficult to demonstrate in invertebrates. Here we show that 1% MgCl2, a muscle relaxant, is a useful adjuvant for the clinical anaesthetic isoflurane on Octopus vulgaris when applied for 10 minutes before the clinical anaesthetic. After this, full anaesthesia can be achieved in 5 minutes using only 1% isoflurane and from which full recovery takes place rapidly in about 10 to 15 minutes. This reduces stress on the animal and minimises the quantity of anaesthetic used.