scholarly journals Live imaging of Aiptasia larvae, a model system for studying coral bleaching, using a simple microfluidic device

2018 ◽  
Author(s):  
Will Van Treuren ◽  
Kara K. Brower ◽  
Louai Labanieh ◽  
Daniel Hunt ◽  
Sarah Lensch ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Coral Bleaching ◽  
Model Organism ◽  
Live Imaging ◽  
Environmental Stressors ◽  
Energy Harvest ◽  
Sea Anemones ◽  
Cellular Mechanisms ◽  
Trap Design ◽  
Algal Symbionts

AbstractCoral reefs, and their associated diverse ecosystems, are of enormous ecological importance. In recent years, coral health has been severely impacted by environmental stressors brought on by human activity and climate change, threatening the extinction of several major reef ecosystems. Reef damage is mediated by a process called ‘coral bleaching’ where corals, sea anemones, and other cnidarians lose their photosynthetic algal symbionts (genus Symbiodinium) upon stress induction, resulting in drastically decreased host energy harvest and, ultimately, coral death. The mechanism by which this critical cnidarian-algal symbiosis is lost remains poorly understood. Here, we report ‘Traptasia’, a simple microfluidic device with multiple traps designed to isolate and image individual live larvae of Aiptasia, a sea anemone model organism, and their algal symbionts over extended time courses. Aiptasia larvae are ~100 μm in length, deformable, and highly motile, posing particular challenges for long-term imaging. Using a trap design optimized via fluid flow simulations and polymer bead loading tests, we trapped Aiptasia larvae containing algal symbionts and demonstrated stable imaging for >10 hours. We visualized algal migration within Aiptasia larvae and observed algal expulsion under an environmental stressor. To our knowledge, this device is the first to enable live imaging of cnidarian larvae and their algal symbionts and, in further implementation, could provide important insights into the cellular mechanisms of coral bleaching under different environmental stressors. The device is simple to use, requires minimal external equipment and no specialized training to operate, and can easily be adapted to study a variety of large, motile organisms.

scholarly journals Watching a deep dive: Live imaging provides lessons about tooth invagination

2016 ◽  
Vol 214 (6) ◽  
pp. 645-647 ◽  
Author(s):  
Amnon Sharir ◽  
Ophir D. Klein
Keyword(s):  
Live Imaging ◽  
Cellular Mechanisms ◽  
Deep Dive ◽  
Critical Step ◽  
Organ Morphogenesis ◽  
Cell Biol ◽  
Mouse Incisor

Invagination of epithelium into the surrounding mesenchyme is a critical step that marks the developmental onset of many ectodermal organs. In this issue, Ahtiainen et al. (2016. J. Cell. Biol. http://dx.doi.org/10.1083/jcb.201512074) use the mouse incisor as a model to advance our understanding of the cellular mechanisms underlying ectodermal organ morphogenesis.

scholarly journals Cephalopod Retinal Development Shows Vertebrate-like Mechanisms of Neurogenesis

2021 ◽  
Author(s):  
Francesca Napoli ◽  
Christina M Daly ◽  
Stephanie Neal ◽  
Kyle J McCulloch ◽  
Alexandra Zaloga ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Nervous System ◽  
Progenitor Cells ◽  
Cellular Proliferation ◽  
Imaging Techniques ◽  
Nuclear Migration ◽  
Live Imaging ◽  
Cellular Mechanisms ◽  
High Resolution Data ◽  
Interkinetic Nuclear Migration

Neurogenesis, the regulation of cellular proliferation and differentiation in the developing nervous system, is the process that underlies the diversity of size and cell type found in animal nervous systems. Our understanding of how this process has evolved is limited because of the lack of high resolution data and live-imaging methods across species. The retina is a classic model for the study of neurogenesis in vertebrates and live-imaging of the retina has shown that during development, progenitor cells are organized in a pseudostratified neuroepithelium and nuclei migrate in coordination with the cell cycle along the apicobasal axis of the cell, a process called interkinetic nuclear migration. Eventually cells delaminate and differentiate within the boundaries of the epithelium. This process has been considered unique to vertebrates and thought to be important in maintaining organization during the development of a complex nervous system. Coleoid cephalopods, including squid, cuttlefish and octopus, have the largest nervous system of any invertebrate and convergently-evolved camera-type eyes, making them a compelling comparative system to vertebrates. Here we have pioneered live-imaging techniques to show that the squid, Doryteuthis pealeii, displays cellular mechanisms during cephalopod retinal neurogenesis that are hallmarks of vertebrate processes. We find that retinal progenitor cells in the squid undergo interkinetic nuclear migration until they exit the cell cycle, we identify retinal organization corresponding to progenitor, post-mitotic and differentiated cells, and we find that Notch signaling regulates this process. With cephalopods and vertebrates having diverged 550 million years ago, these results suggest that mechanisms thought to be unique to vertebrates may be common to highly proliferative neurogenic primordia contributing to a large nervous system.

scholarly journals Flexibility of nutritional strategies within a mutualism: food availability affects algal symbiont productivity in two congeneric sea anemone species

2020 ◽  
Vol 287 (1940) ◽  
pp. 20201860
Author(s):  
Samuel A. Bedgood ◽  
Sarah E. Mastroni ◽  
Matthew E. S. Bracken
Keyword(s):  
Food Availability ◽  
Sea Anemone ◽  
Symbiotic Association ◽  
Sea Anemones ◽  
External Resources ◽  
Carbon And Nitrogen ◽  
Algal Symbionts ◽  
Algal Symbiont ◽  
Nutritional Strategy ◽  
Nutritional Strategies

Mutualistic symbioses are common, especially in nutrient-poor environments where an association between hosts and symbionts can allow the symbiotic partners to persist and collectively out-compete non-symbiotic species. Usually these mutualisms are built on an intimate transfer of energy and nutrients (e.g. carbon and nitrogen) between host and symbiont. However, resource availability is not consistent, and the benefit of the symbiotic association can depend on the availability of resources to mutualists. We manipulated the diets of two temperate sea anemone species in the genus Anthopleura in the field and recorded the responses of sea anemones and algal symbionts in the family Symbiodiniaceae to our treatments. Algal symbiont density, symbiont volume and photosynthetic efficiency of symbionts responded to changes in sea anemone diet, but the responses depended on the species of sea anemone. We suggest that temperate sea anemones and their symbionts can respond to changes in anemone diet, modifying the balance between heterotrophy and autotrophy in the symbiosis. Our data support the hypothesis that symbionts are upregulated or downregulated based on food availability, allowing for a flexible nutritional strategy based on external resources.

scholarly journals Drosophila Neuronal Injury Follows a Temporal Sequence of Cellular Events Leading to Degeneration at the Neuromuscular Junction

2015 ◽  
Vol 9s2 ◽  
pp. JEN.S25516 ◽  
Author(s):  
Barron L. Lincoln ◽  
Sahar H. Alabsi ◽  
Nicholas Frendo ◽  
Robert Freund ◽  
Lani C. Keller
Keyword(s):  
Neuromuscular Junction ◽  
Model Organism ◽  
Structural Defects ◽  
Cellular Mechanisms ◽  
Post Injury ◽  
Ubiquitinated Proteins ◽  
Cellular Events ◽  
Molecular Events ◽  
Complex Signaling

Neurodegenerative diseases affect millions of people worldwide, and as the global population ages, there is a critical need to improve our understanding of the molecular and cellular mechanisms that drive neurodegeneration. At the molecular level, neurodegeneration involves the activation of complex signaling pathways that drive the active destruction of neurons and their intracellular components. Here, we use an in vivo motor neuron injury assay to acutely induce neurodegeneration in order to follow the temporal order of events that occur following injury in Drosophila melanogaster. We find that sites of injury can be rapidly identified based on structural defects to the neuronal cytoskeleton that result in disrupted axonal transport. Additionally, the neuromuscular junction accumulates ubiquitinated proteins prior to the neurodegenerative events, occurring at 24 hours post injury. Our data provide insights into the early molecular events that occur during axonal and neuromuscular degeneration in a genetically tractable model organism. Importantly, the mechanisms that mediate neurodegeneration in flies are conserved in humans. Thus, these studies have implications for our understanding of the cellular and molecular events that occur in humans and will facilitate the identification of biomedically relevant targets for future treatments.

scholarly journals The Ecological Importance of Toxicity: Sea Anemones Maintain Toxic Defence When Bleached

Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 266 ◽  
Author(s):  
Cassie M. Hoepner ◽  
Catherine A. Abbott ◽  
Karen Burke da Silva
Keyword(s):  
Food Source ◽  
Environmental Stressors ◽  
Sea Anemones ◽  
Venomous Animals ◽  
Ecological Importance ◽  
Endosymbiotic Algae ◽  
Entacmaea Quadricolor ◽  
Impacts Of Climate Change

Cnidarians are amongst the most venomous animals on the planet. They are also under significant threat due to the impacts of climate change. Corals and anemones undergo climate-induced bleaching during extreme environmental conditions, where a loss of symbiotic photosynthetic algae (zooxanthellae) causes whitening in colour, loss of internal food supply, and reduction in health, which can ultimately lead to death. What has yet to be determined is whether bleaching causes a reduction in the production or quality of venom. In this study, the sea anemone Entacmaea quadricolor was exposed to long-term light-induced bleaching to examine the effect that bleaching has on venom. Venom quality and quantity, as determined through lethality and haemolysis measures and nematocyst production was highly preserved over the five-month imposed bleaching event. Maintenance of venom and nematocyst production, despite a loss of an internal food source provided by endosymbiotic algae, indicates both the ecological importance of maintaining toxicity and a remarkable resilience that anemones have to major environmental stressors.

scholarly journals A coral-on-a-chip microfluidic platform enabling live-imaging microscopy of reef-building corals

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Orr H. Shapiro ◽  
Esti Kramarsky-Winter ◽  
Assaf R. Gavish ◽  
Roman Stocker ◽  
Assaf Vardi
Keyword(s):  
Live Imaging ◽  
Live Coral ◽  
Powerful Method ◽  
Microfluidic Platform ◽  
Experimental Platform ◽  
Micro Scale ◽  
Algal Symbionts ◽  
Spatio Temporal

Abstract Coral reefs, and the unique ecosystems they support, are facing severe threats by human activities and climate change. Our understanding of these threats is hampered by the lack of robust approaches for studying the micro-scale interactions between corals and their environment. Here we present an experimental platform, coral-on-a-chip, combining micropropagation and microfluidics to allow direct microscopic study of live coral polyps. The small and transparent coral micropropagates are ideally suited for live-imaging microscopy, while the microfluidic platform facilitates long-term visualization under controlled environmental conditions. We demonstrate the usefulness of this approach by imaging coral micropropagates at previously unattainable spatio-temporal resolutions, providing new insights into several micro-scale processes including coral calcification, coral–pathogen interaction and the loss of algal symbionts (coral bleaching). Coral-on-a-chip thus provides a powerful method for studying coral physiology in vivo at the micro-scale, opening new vistas in coral biology.

scholarly journals A microfluidic device and computational platform for high-throughput live imaging of gene expression

2012 ◽  
Vol 9 (11) ◽  
pp. 1101-1106 ◽  
Author(s):  
Wolfgang Busch ◽  
Brad T Moore ◽  
Bradley Martsberger ◽  
Daniel L Mace ◽  
Richard W Twigg ◽  
...  
Keyword(s):  
Gene Expression ◽  
Microfluidic Device ◽  
High Throughput ◽  
Live Imaging ◽  
Computational Platform

scholarly journals An algal symbiont (Breviolum psygmophilum) responds more strongly to chronic high temperatures than its facultatively symbiotic coral host (Astrangia poculata)

2021 ◽  
Author(s):  
Andrea N. Chan ◽  
Luis A. González-Guerrero ◽  
Roberto Iglesias-Prieto ◽  
Elizabeth M. Burmester ◽  
Randi D. Rotjan ◽  
...  
Keyword(s):  
Heat Stress ◽  
Thermal Stress ◽  
Stress Response ◽  
Coral Bleaching ◽  
Scleractinian Corals ◽  
Coral Host ◽  
Algal Symbionts ◽  
Algal Symbiont ◽  
Astrangia Poculata ◽  
And Control

AbstractScleractinian corals form the foundation of coral reefs by secreting skeletons of calcium carbonate. Their intracellular algal symbionts (Symbiodiniaceae) translocate a large proportion of photosynthate to the coral host, which is required to maintain high rates of calcification. Global warming is causing dissociation of coral host and algal symbiont, visibly presented as coral bleaching. Despite decades of study, the precise mechanisms of coral bleaching remain unknown. Separating the thermal stress response of the coral from the algal symbiont is key to understanding bleaching in tropical corals. The facultatively symbiotic northern star coral, Astrangia poculata, naturally occurs as both symbiotic and aposymbiotic (lacking algal symbionts) polyps – sometimes on the same coral colony. Thus, it is possible to separate the heat stress response of the coral host alone from the coral in symbiosis with its symbiont Breviolum psygmophilum. Using replicate symbiotic and aposymbiotic ramets of A. poculata, we conducted a chronic heat stress experiment to increase our understanding of the cellular mechanisms resulting in coral bleaching. Sustained high temperature stress resulted in photosynthetic dysfunction in B. psygmophilum, including a decline in maximum photosynthesis rate, maximum photochemical efficiency, and the absorbance peak of chlorophyll a. Interestingly, the metabolic rates of symbiotic and aposymbiotic corals were differentially impacted. RNAseq analysis revealed more differentially expressed genes between heat-stressed and control aposymbiotic colonies than heat-stressed and control symbiotic colonies. Notably, aposymbiotic colonies increased the expression of inflammation-associated genes such as nitric oxide synthases. Unexpectedly, the largest transcriptional response was observed between heat-stressed and control B. psygmophilum, including genes involved in photosynthesis, response to oxidative stress, and meiosis. Thus, it appears that the algal symbiont suppresses the immune response of the host, potentially increasing the vulnerability of the host to pathogens. The A. poculata-B. psygmophilum symbiosis provides a tractable model system for investigating thermal stress and immune challenge in scleractinian corals.

scholarly journals Honey bee as an alternative model invertebrate organism

2025 ◽  
Vol 74 (10) ◽  
pp. 6140-2025
Author(s):  
ALEKSANDRA ŁOŚ ◽  
MAŁGORZATA BIEŃKOWSKA ◽  
ANETA STRACHECKA
Keyword(s):  
Collective Intelligence ◽  
Lethal Dose ◽  
Genetic Research ◽  
Model Organism ◽  
Model Organisms ◽  
Cellular Mechanisms ◽  
Bee Colony ◽  
Proboscis Extension ◽  
The Individual ◽  
Explosive Devices

Insects perfectly fit the flagship principle of animal research – 3R: to reduce (the number of animals), to replace (animals with alternative models) and to refine (methods). Bees have the most important advantages of a model organism: they cause minimal ethical controversy, they have a small and fully known genome, and they permit the use of many experimental techniques. Bees have a fully functional DNMT toolkit. Therefore, they are used as models in biomedical/genetic research, e.g. in research on the development of cancer or in the diagnostics of mental and neuroleptic diseases in humans. The reversion of aging processes in bees offers hope for progress in gerontology research. The cellular mechanisms of learning and memory coding, as well as the indicators of biochemical immunity parameters, are similar or analogous to those in humans, so bees may become useful in monitoring changes in behavior and metabolism. Bees are very well suited for studies on the dose of the substance applied to determine the lethal dose or the effect of a formula on life expectancy. Honeybees have proven to be an effective tool for studying the effects of a long-term consumption of stimulants, as well as for observing behavioral changes and developing addictions at the individual and social levels, as well as for investigating the effects of continuously delivering the same dose of a substance. The genomic and physiological flexibility of bees in dividing tasks among workers in a colony makes it possible to create a Single- Cohort Colony (SCC) in which peers compared perform different tasks. Moreover behavioral methods (e.g. Proboscis Extension Reflex – PER, Sting Extension Reflex – SER, free flying target discrimination tasks or the cap pushing response) make it possible to analyse changes occurring in honeybee brains during learning and remembering. Algorithms of actions are created based on the behavior of a colony or individual, e.g. Artificial Bee Colony Algorithm (ABCA). Honeybees are also model organisms for profiling the so-called intelligence of a swarm or collective intelligence. Additionally, they serve as models for guidance systems and aviation technologies. Bees have inspired important projects in robotics, such as B-droid, Robobee and The Green Brain Project. It has also been confirmed that the apian sense of smell can be used to detect explosive devices, such as TNT, or drugs (including heroin, cocaine, amphetamines and cannabis). This inconspicuous little insect can revolutionize the world of science and contribute to the solution of many scientific problems as a versatile model.

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