Linalool Acts As A Fast And Reversible Anesthetic In Hydra

The ability to make transgenic Hydra lines has allowed for quantitative in vivo studies of Hydra regeneration and physiology. These studies commonly include excision, grafting and transplantation experiments along with high-resolution imaging of live animals, which can be challenging due to the animal’s response to touch and light stimuli. While various anesthetics have been used in Hydra studies, they tend to be toxic over the course of a few hours or their long-term effects on animal health are unknown. Here, we show that the monoterpenoid alcohol linalool is a useful anesthetic for Hydra. Linalool is easy to use, non-toxic, fast acting, and reversible. It has no detectable long-term effects on cell viability or cell proliferation. We demonstrate that the same animal can be immobilized in linalool multiple times at intervals of several hours for repeated imaging over 2–3 days. This uniquely allows for in vivo imaging of dynamic processes such as head regeneration. We directly compare linalool to currently used anesthetics and show its superior performance. Linalool will be a useful tool for tissue manipulation and imaging in Hydra research in both research and teaching contexts

Handbook of Marine Model Organisms in Experimental Biology

"The importance of molecular approaches for comparative biology and the rapid development of new molecular tools is unprecedented. The extraordinary molecular progress belies the need for understanding the development and basic biology of whole organisms. Vigorous international efforts to train the next-generation of experimental biologists must combine both levels – next generation molecular approaches and traditional organismal biology. This book provides cutting-edge chapters regarding the growing list of marine model organisms. Access to and practical advice on these model organisms have become aconditio sine qua non for a modern education of advanced undergraduate students, graduate students and postdocs working on marine model systems. Model organisms are not only tools they are also bridges between fields – from behavior, development and physiology to functional genomics. Key Features Offers deep insights into cutting-edge model system science Provides in-depth overviews of all prominent marine model organisms Illustrates challenging experimental approaches to model system research Serves as a reference book also for next-generation functional genomics applications Fills an urgent need for students Related Titles Jarret, R. L. & K. McCluskey, eds. The Biological Resources of Model Organisms (ISBN 978-1-1382-9461-5) Kim, S.-K. Healthcare Using Marine Organisms (ISBN 978-1-1382-9538-4) Mudher, A. & T. Newman, eds. Drosophila: A Toolbox for the Study of Neurodegenerative Disease (ISBN 978-0-4154-1185-1) Green, S. L. The Laboratory Xenopus sp. (ISBN 978-1-4200-9109-0)

Whole-Body Regeneration

This Open Access volume provides a comprehensive overview of the latest tools available to scientists to study the many facets of whole-body regeneration (WBR). The chapters in this book are organized into six parts. Part One provides a historical overview on the study of the WBR phenomena focusing on the primary challenges of this research. Parts Two and Three explore a series of non-vertebrate zoological contexts that provide experimental models for WBR, showing how they can be approached with cellular tools. Parts Four, Five, and Six discuss the future advancements of WBR, reporting about the cutting-edge techniques in genetics and omics used to dissect the underlying mechanisms of WBR, and systems biology approaches to reach a synthetic view of WBR. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and thorough, Whole-Body Regeneration: Methods and Protocols is a valuable resource for scientists and researchers who want to learn more about this important and developing field

Whole-Body Regeneration

This Open Access volume provides a comprehensive overview of the latest tools available to scientists to study the many facets of whole-body regeneration (WBR). The chapters in this book are organized into six parts. Part One provides a historical overview on the study of the WBR phenomena focusing on the primary challenges of this research. Parts Two and Three explore a series of non-vertebrate zoological contexts that provide experimental models for WBR, showing how they can be approached with cellular tools. Parts Four, Five, and Six discuss the future advancements of WBR, reporting about the cutting-edge techniques in genetics and omics used to dissect the underlying mechanisms of WBR, and systems biology approaches to reach a synthetic view of WBR. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and thorough, Whole-Body Regeneration: Methods and Protocols is a valuable resource for scientists and researchers who want to learn more about this important and developing field

An endocannabinoid system in the neuroendocrine and autonomic nervous system of rodents

Leben bedeutet eine fortdauernde Anpassung an Umweltbedingungen durch ein hoch entwickeltes Informationsverarbeitungssystem. Diese Anpassung wird durch das neuroendokrine und autonome Nervensystem gewährleistet. Eine tages- und jahreszeitliche Organisation des neuroendokrinen und autonomen Systems findet durch das Photoneuroendokrine System (PNS) statt. Erst in jüngster Zeit konnte gezeigt werden, dass neben peptidergen Substanzen auch lipiderge Signalmoleküle des Endocannabinoidsystems eine essentielle Rolle bei der interzelluären Kommunikation spielen. Hierbei zählen Anandamid (AEA) und 2-Arachidonoylglycerol (2-AG) zu den umfassend erforschten Endocannabinoiden. ...Life means a continuous adaptation to environmental conditions through a highly developed information processing system. The neuroendocrine and autonomic nervous systems ensure such adaptation. The photoneuroendocrine system provides a diurnal and seasonal organisation of the neuroendocrine and autonomic system. Recent data indicated that beyond peptidergic substances also lipidergic signal molecules of the endocannabinoid system play an important role in intercellular communication. Anandamide (AEA) and 2-Arachidonoylglycerol (2-AG) are the best investigated endocannabinoids to date. Both endocannabinoids are synthesized on demand from membrane lipids. Anandamide is synthesized by a calcium dependent, selective phospholipase D (NAPE-PLD) from anandamide precursor N-arachidonoylphosphatidylethanolamine (NAPE). ..

Ingestion-Egestion Dynamics and Palatability of Microplastics With/Without Biofilm in Jellyfish and Polyps of Aurelia Aurita (Linnaeus, 1758)

[Resumen] La ubicuidad de los microplásticos (MP) y el pequeño tamaño que presentan, los hace disponibles para una amplia gama de organismos marinos, entre ellos los cnidarios. Se ha llevado a cabo un estudio para comprobar la dinámica de ingestión-egestión y la palatabilidad de diferentes MP con y sin biofilm tanto en la fase pólipo como en la fase medusa de Aurelia aurita. Además, se ha realizado una verificación de si aquellas medusas de mayor tamaño captan y se introducen en la cavidad gástrica mayor cantidad de MP. Los resultados han revelado diferencias significativas en medusas a la hora de captar los MP con los tentáculos e introducírselos en la cavidad gástrica. Se ha obtenido un mayor porcentaje de fibras con biofilm que capta en los tentáculos, sin embargo, se introducen en la cavidad un mayor porcentaje de fibras sin biofilm. En relación a los pólipos, no se han obtenido diferencias significativas en cuanto a la palatabilidad de los diferentes MP. No se han hallado diferencias significativas en los tiempos medios de ingestión y egestión en medusas y pólipos. Finalmente, no se ha observado una correlación entre el número de MP que capta o se introduce en la cavidad gástricas y el diámetro de la umbrela de las medusas.[Abstract] The ubiquity of microplastics (MP) and their small size makes them available to a wide range of marine organisms, including cnidarians. A study was carried out to test the ingestion-eggestion dynamics and palatability of different MP with and without biofilm in both the polyp and medusa stages of Aurelia aurita. Also, the average time of ingestion and egestion of these polymers in both phases has been obtained. In addition, it has been verified whether larger jellyfish capture and enter the gastric cavity a greater amount of MP. The results have revealed significant differences in jellyfish when it comes to capturing MP with their tentacles and introducing them into the gastric cavity. A higher percentage of fibres with biofilm was obtained from the tentacles, but a higher percentage of fibres without biofilm were introduced into the cavity. With regard to polyps, no significant differences were found in the palatability of the different MPs. No significant differences were found in the mean ingestion and egestion times of jellyfish and polyps. Finally, no correlation was observed between the number of MPs taken up or introduced into the gastric cavity and the diameter of the jellyfish umbrela.Este trabajo ha sido elaborado en instalaciones de la Universidad de Alicante, en concreto en la Estación Científica Montgó-Dénia y ha contado con co-financiación del Ayuntamiento de Dénia y de la Generalitat Valenciana (Conselleria de Agricultura, Desarrollo Rural, Emergencia Climática y Transición Ecológica). También ha tenido co-financiación del proyecto "A comprehensive marine observatory in the coast of Marina Alta for the conservation of biodiversity, observtion of global change and promotion of the blue economy (OBSERMAR-CV ThinkinAzul)"Traballo fin de mestrado (UDC.CIE). Bioloxía mariña. Curso 2021/202

Bioactive Molecules from Extreme Environments II

This Special Issue, as a continuation of the previous Special Issue, “Bioactive Molecules from Extreme Environments” (https://www.mdpi.com/journal/marinedrugs/special_issues/Extreme_Environments accessed on 4 November 2021), includes 10 research articles and 2 reviews, providing a wide overview of the chemical biodiversity offered by different marine organisms inhabiting extreme environments to be used for biotechnological and pharmaceutical applications. The six articles in this Special Issue are focused on the polar regions, which represent an untapped source of marine natural products and are still largely unexplored compared to more accessible sites. Many of these articles refer to Antarctica, which is the coldest and most inaccessible continent on the Earth, where extreme temperatures, light and ice have selected biological communities with a unique suite of bioactive metabolites. The marine organisms of Arctic and Antarctic environments are a reservoir of natural compounds, exhibiting huge structural diversity and significant bioactivities that could be used in human applications

The function of mechanosensory systems in the startle behavior of planktonic larvae

The sensation of mechanical stimuli is a central function of all animal nervous systems. Mechanosensory systems are in charge of this function, using for that a set of specialized molecules and cells that transmit the signal to downstream circuits that initiate and guide a wide variety of behaviors, ranging from navigation, to social interactions. Despite the intensive study of mechanosensory systems in the main genetics models, a clear unified picture of these sensory systems is still lacking. Exploring mechanosensory systems in animals spread across the phylogeny may help reveal such common principles. To contribute towards this aim, the mechanosensory systems of the planktonic larva of the marine annelid Platynereis dumerilii are analysed in this work using genetics, circuit and behavioral approaches. At the behavioral level, a startle response elicited by mechanical stimuli is described in Platynereis larvae using high-speed recordings. This startle response is a fast and well-coordinated behavior involving the control of both the muscular and ciliary locomotor systems of the larva. The startle response is shown to be modulated according to the intensity and site of stimulation. Such responses have been observed in other planktonic organisms, but the mechanosensory cells responsible for initiating the response are not known. A group of penetrating uniciliated neurons in the Platynereis larva are shown by calcium imaging to respond to the mechanical stimuli eliciting the startle response. Their morphology is quite similar to putative mechanosensory cells found in other animals, thus suggesting a deep evolutionary conservation. It is not entirely understood what molecular and cellular mechanisms are required for transforming mechanical cues to cellular signals. Here it is shown that Platynereis has homologs to the main molecules that have been implicated in mechanotransduction. The ciliated hydrodynamic receptors identified in this study express PKD1-1 and PKD2-1, two members of the polycystin family that have been implicated in mechanotransduction in other animals. The CRISPR system is used to generate frame-shift mutations in these genes. The mutants no longer display the startle response upon mechanical stimulation, thus suggesting that PKD2-1 and PKD1-1 are essential for the transmission of the mechanical information to downstream circuitries. Startle behaviors generally have a role in avoiding, escaping or deterring predators. It is however not clear what specific adaptations are most useful to increase survival. Here, I used the mutants defective in the startle response to assess the survival value of this behavior. Competition experiments using a rheotactic planktonic predator showed that the mutants are predated more than their wildtype counterparts. These results show that seemingly simple behavioral adaptions can have a high adaptive value. Due to their relatively simplicity, startle responses such as the one described for Platynereis have been dissected at the circuit level. Here, the startle circuit of Platynereis larvae is reconstructed at the synapse level using serial transmission electron microscopy. The resulting circuit shows direct and indirect pathways that explain how ciliary bands and muscles are controlled in a coordinated and synchronous manner. A novel group of interneurons and motoneurons is described that provides candidates for further functional exploration of this circuit.Die Wahrnehmung mechanischer Reize ist eine zentrale Funktion der Nervensysteme aller Tiere. Mechanosensorische Systeme nutzen ein Set von speziellen Molekülen und Zellen, die das Signal des mechanischen Reizes an das postsynaptische neuronale Netzwerk weiterleiten und eine Vielzahl von Verhalten, von Navigation bis zu sozialer Interaktion, induzieren und beeinflussen. Trotz intensiver Forschung der mechanosensorischen Systeme in den wichtigsten genetischen Modelorganismen fehlt ein klares, einheitliches Bild. Dies kann durch die Untersuchung der mechanosensorischen Systeme in Tieren aus weiteren phylogenetischen Gruppen erweitert werden und hilft somit allgemeine Prinzipien hervorzuheben. Um sich diesem Ziel zu nähern, werden in dieser Arbeit die mechanosensorischen Systeme der planktischen Larve des marinen Ringelwurms Platynereis dumerilii, auf der Ebene von Genetik, neuronalen Schaltreisen und Verhalten, analysiert. Auf Verhaltensebene wird eine Schreckreaktion durch mechanische Reize in der Platynereis Larve ausgelöst und mit Hilfe von Hochgeschwindigkeitsaufnahmen beschrieben. Diese Schreckreaktion ist ein schnelles und gut koordiniertes Verhalten, welches die Kontrolle von Muskeln und Zilien in der Larve involviert und durch die Reizintensität und dem Ort der Reizapplikation verändert werden kann. Andere planktische Organismen zeigen ähnliche Reaktion, aber die mechanosensorischen Zellen, die dieses Verhalten verursachen, sind nicht bekannt. In Platynereis Larven konnte eine Gruppe von Nervenzellen mit je einer, die Kutikula durchdringenden, Zilie identifiziert werden. Durch Kalziumindikatoren konnte gezeigt werden, dass diese Neurone auf mechanische Reize reagieren, welche die Schreckreaktion auslösen. Ihre Morphologie ist den, in anderen Tieren gefundenen, mutmaßlichen mechanosensorischen Zellen sehr ähnlich, welches eine evolutionäre Konservierung annehmen lässt. Es ist nicht vollständig verstanden, welche molekularen und zellulären Mechanismen für die Umwandlung mechanischer Reize in zellulare Signale verantwortlich sind. Hier wird gezeigt, dass Platynereis Moleküle besitzt, welche homolog zu den Molekülen sind, denen eine Beteiligung an der Weiterleitung des mechanosensorischen Reizes nachgesagt wird. Die bewimperten hydrodynamischen Rezeptoren, die in dieser Studie identifiziert worden, exprimieren PKD1-1 und PKD2-1, zwei Mitglieder der Polycystin Familie, welche in anderen Tieren mutmaßlich an der mechanosensorischen Weiterleitung beteiligt sind. Larven mit einer Rastermutation auf diesen Genen, welche mittels dem CRISPR System erzeugt wurde, zeigen keine Schreckreaktion nach mechanischer Stimulation. Das lässt vermuten, dass PKD2-1 und PKD1-1 für die Weiterleitung der mechanischen Reizinformation an das postsynaptische neuronale Netzwerk essentiell sind. Schreckreaktionsverhalten spielt im allgemeinen eine Rolle in der Vermeidung, Flucht oder Abschreckung von Räubern. Jedoch ist nicht eindeutig geklärt welche spezifischen Adaptionen besonders nützlich für das Überleben sind. In der vorliegenden Studie werden die mutierten Larven ohne Schreckreaktion genutzt, um die Bedeutung des Verhaltens für das Überleben zu bewerten. Die Experimente mit einem rheotaktischen Räuber zeigen, dass mehr mutierte Larven als Wildtyp-Larven gefressen werden. Diese Ergebnisse zeigen, dass scheinbar einfache Verhaltensanpassungen einen großen Effekt haben können. Hier wird die Schreckreaktion in Platynereis Larven auf dem Level von neuronalen Schaltkreisen mit synaptischer Auflösung durch Serien-Transmission-Elektronen-Mikroskopie untersucht. Der daraus resultierende neuronale Schaltkreis zeigt direkte und indirekte Wege, die erklären wie Zilienbänder und Muskeln koordiniert und synchron kontrolliert werden. Außerdem wird eine neue Gruppe von Interneuronen und Motorneuronen beschrieben und liefert Kandidaten für weitere funktionale Erkundigungen des neuronalen Schaltkreises