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Hüppe L, Bahlburg D, Busack M, Lemburg J, Payton L, Reinhard N, Rieger D, Helfrich-Förster C, Meyer B. A new Activity Monitor for Aquatic Zooplankter (AMAZE) allows the recording of swimming activity in wild-caught Antarctic krill (Euphausia superba). Sci Rep 2024; 14:16963. [PMID: 39043920 PMCID: PMC11266396 DOI: 10.1038/s41598-024-67999-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Accepted: 07/18/2024] [Indexed: 07/25/2024] Open
Abstract
Antarctic krill (Euphausia superba, hereafter krill) is a pelagic living crustacean and a key species in the Southern Ocean ecosystem. Krill builds up a huge biomass and its synchronized behavioral patterns, such as diel vertical migration (DVM), substantially impact ecosystem structure and carbon sequestration. However, the mechanistic basis of krill DVM is unknown and previous studies of krill behavior in the laboratory were challenged by complex behavior and large variability. Using a new experimental set-up, we recorded the swimming activity of individual wild-caught krill under light-dark cycles. Krill individuals exhibited differential phototactic responses to the light regime provided. However, using a new activity metric, we showed for the first time a consistent nocturnal increase in krill swimming activity in a controlled environment. Krill swimming activity in the new set-up was strongly synchronized with the light-dark cycle, similar to the diel vertical migration pattern of krill in the field when the krill were sampled for the experiment, demonstrated by hydroacoustic recordings. The new set-up presents a promising tool for investigating the mechanisms underlying krill behavioral patterns, which will increase our understanding of ecological interactions, the spatial distribution of populations, and their effects on biogeochemical cycles in the future.
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Affiliation(s)
- Lukas Hüppe
- Neurobiology and Genetics, University of Würzburg, Biocentre, Theodor-Boveri-Institute, Am Hubland, 97074, Würzburg, Germany.
- Section Polar Biological Oceanography, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
| | - Dominik Bahlburg
- Section Polar Biological Oceanography, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Michael Busack
- Section Deep-Sea Ecology and Technology, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Johannes Lemburg
- Scientific Workshop, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Laura Payton
- Section Polar Biological Oceanography, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
- CNRS, INP, EPOC, UMR 5805, University of Bordeaux, 33120, Arcachon, Bordeaux, France
| | - Nils Reinhard
- Neurobiology and Genetics, University of Würzburg, Biocentre, Theodor-Boveri-Institute, Am Hubland, 97074, Würzburg, Germany
| | - Dirk Rieger
- Neurobiology and Genetics, University of Würzburg, Biocentre, Theodor-Boveri-Institute, Am Hubland, 97074, Würzburg, Germany
| | - Charlotte Helfrich-Förster
- Neurobiology and Genetics, University of Würzburg, Biocentre, Theodor-Boveri-Institute, Am Hubland, 97074, Würzburg, Germany
| | - Bettina Meyer
- Section Polar Biological Oceanography, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Carl-Von-Ossietzky-Straße 9-11, 26111, Oldenburg, Germany.
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstrasse 231, 26129, Oldenburg, Germany.
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Abe S, Takahata Y, Miyakawa H. Daphnia uses its circadian clock for short-day recognition in environmental sex determination. Curr Biol 2024; 34:2002-2010.e3. [PMID: 38579713 DOI: 10.1016/j.cub.2024.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 02/12/2024] [Accepted: 03/14/2024] [Indexed: 04/07/2024]
Abstract
Some organisms have developed a mechanism called environmental sex determination (ESD), which allows environmental cues, rather than sex chromosomes or genes, to determine offspring sex.1,2,3,4 ESD is advantageous to optimize sex ratios according to environmental conditions, enhancing reproductive success.5,6 However, the process by which organisms perceive and translate diverse environmental signals into offspring sex remains unclear. Here, we analyzed the environmental perception mechanism in the crustacean, Daphnia pulex, a seasonal (photoperiodic) ESD arthropod, capable of producing females under long days and males under short days.7,8,9,10 Through breeding experiments, we found that their circadian clock likely contributes to perception of day length. To explore this further, we created a genetically modified daphnid by knocking out the clock gene, period, using genome editing. Knockout disrupted the daphnid's ability to sustain diel vertical migration (DVM) under constant darkness, driven by the circadian clock, and leading them to produce females regardless of day length. Additionally, when exposed to an analog of juvenile hormone (JH), an endocrine factor synthesized in mothers during male production, or subjected to unfavorable conditions of high density and low food availability, these knockout daphnids produced males regardless of day length, like wild-type daphnids. Based on these findings, we propose that recognizing short days via the circadian clock is the initial step in sex determination. This recognition subsequently triggers male production by signaling the endocrine system, specifically via the JH signal. Establishment of a connection between these two processes may be the crucial element in evolution of ESD in Daphnia.
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Affiliation(s)
- Shione Abe
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
| | - Yugo Takahata
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
| | - Hitoshi Miyakawa
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan.
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Timmins-Schiffman E, Maas AE, Khanna R, Blanco-Bercial L, Huang E, Nunn BL. Removal of Exogenous Stimuli Reveals a Canalization of Circadian Physiology in a Vertically Migrating Copepod. J Proteome Res 2024. [PMID: 38690632 DOI: 10.1021/acs.jproteome.4c00086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Diel rhythms are observed across taxa and are important for maintaining synchrony between the environment and organismal physiology. A striking example of this is the diel vertical migration undertaken by zooplankton, some of which, such as the 5 mm-long copepod Pleuromamma xiphias (P. xiphias), migrate hundreds of meters daily between the surface ocean and deeper waters. Some of the molecular pathways that underlie the expressed phenotype at different stages of this migration are entrained by environmental variables (e.g., day length and food availability), while others are regulated by internal clocks. We identified a series of proteomic biomarkers that vary across ocean DVM and applied them to copepods incubated in 24 h of darkness to assess circadian control. The dark-incubated copepods shared some proteomic similarities to the ocean-caught copepods (i.e., increased abundance of carbohydrate metabolism proteins at night). Shipboard-incubated copepods demonstrated a clearer distinction between night and day proteomic profiles, and more proteins were differentially abundant than in the in situ copepods, even in the absence of the photoperiod and other environmental cues. This pattern suggests that there is a canalization of rhythmic diel physiology in P. xiphias that reflects likely circadian clock control over diverse molecular pathways.
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Affiliation(s)
- Emma Timmins-Schiffman
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
| | - Amy E Maas
- Bermuda Institute of Ocean Sciences, Arizona State University, St. George's 98C3+8F, Bermuda
| | - Rayhan Khanna
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
- Cornell University, Ithaca, New York 14850, United States
| | - Leocadio Blanco-Bercial
- Bermuda Institute of Ocean Sciences, Arizona State University, St. George's 98C3+8F, Bermuda
| | - Eric Huang
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
- Just-Evotec Biologics, Seattle, Washington 98109, United States
| | - Brook L Nunn
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
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Maas AE, Timmins-Schiffman E, Tarrant AM, Nunn BL, Park J, Blanco-Bercial L. Diel metabolic patterns revealed by in situ transcriptome and proteome in a vertically migratory copepod. Mol Ecol 2024; 33:e17284. [PMID: 38258354 DOI: 10.1111/mec.17284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 12/06/2023] [Accepted: 12/21/2023] [Indexed: 01/24/2024]
Abstract
Zooplankton undergo a diel vertical migration (DVM) which exposes them to gradients of light, temperature, oxygen, and food availability on a predictable daily schedule. Disentangling the co-varying and potentially synergistic interactions on metabolic rates has proven difficult, despite the importance of this migration for the delivery of metabolic waste products to the distinctly different daytime (deep) and nighttime (surface) habitats. This study examines the transcriptomic and proteomic profiles of the circumglobal migratory copepod, Pleuromamma xiphias, over the diel cycle. The transcriptome showed that 96% of differentially expressed genes were upregulated during the middle of the day - the period often considered to be of lowest zooplankton activity. The changes in protein abundance were more spread out over time, peaking (42% of comparisons) in the early evening. Between 9:00 and 15:00, both the transcriptome and proteome datasets showed increased expression related to chitin synthesis and degradation. Additionally, at 09:00 and 22:00, there were increases in myosin and vitellogenin proteins, potentially linked to the stress of migration and/or reproductive investment. Based on protein abundances detected, there is an inferred switch in broad metabolic processes, shifting from electron transport system in the day to glycolysis and glycogen mobilization in the afternoon/evening. These observations provide evidence of the diel impact of DVM on transcriptomic and proteomic pathways that likely influence metabolic processes and subsequent excretion products, and clarify how this behaviour results in the direct rapid transport of waste metabolites from the surface to the deep ocean.
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Affiliation(s)
- Amy E Maas
- Bermuda Institute of Ocean Sciences, School of Ocean Futures, Arizona State University, St. George's, Bermuda
| | | | - Ann M Tarrant
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Brook L Nunn
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Jea Park
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - Leocadio Blanco-Bercial
- Bermuda Institute of Ocean Sciences, School of Ocean Futures, Arizona State University, St. George's, Bermuda
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Cheng CHC, Rivera-Colón AG, Minhas BF, Wilson L, Rayamajhi N, Vargas-Chacoff L, Catchen JM. Chromosome-Level Genome Assembly and Circadian Gene Repertoire of the Patagonia Blennie Eleginops maclovinus-The Closest Ancestral Proxy of Antarctic Cryonotothenioids. Genes (Basel) 2023; 14:1196. [PMID: 37372376 DOI: 10.3390/genes14061196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/26/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
The basal South American notothenioid Eleginops maclovinus (Patagonia blennie or róbalo) occupies a uniquely important phylogenetic position in Notothenioidei as the singular closest sister species to the Antarctic cryonotothenioid fishes. Its genome and the traits encoded therein would be the nearest representatives of the temperate ancestor from which the Antarctic clade arose, providing an ancestral reference for deducing polar derived changes. In this study, we generated a gene- and chromosome-complete assembly of the E. maclovinus genome using long read sequencing and HiC scaffolding. We compared its genome architecture with the more basally divergent Cottoperca gobio and the derived genomes of nine cryonotothenioids representing all five Antarctic families. We also reconstructed a notothenioid phylogeny using 2918 proteins of single-copy orthologous genes from these genomes that reaffirmed E. maclovinus' phylogenetic position. We additionally curated E. maclovinus' repertoire of circadian rhythm genes, ascertained their functionality by transcriptome sequencing, and compared its pattern of gene retention with C. gobio and the derived cryonotothenioids. Through reconstructing circadian gene trees, we also assessed the potential role of the retained genes in cryonotothenioids by referencing to the functions of the human orthologs. Our results found E. maclovinus to share greater conservation with the Antarctic clade, solidifying its evolutionary status as the direct sister and best suited ancestral proxy of cryonotothenioids. The high-quality genome of E. maclovinus will facilitate inquiries into cold derived traits in temperate to polar evolution, and conversely on the paths of readaptation to non-freezing habitats in various secondarily temperate cryonotothenioids through comparative genomic analyses.
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Affiliation(s)
- Chi-Hing Christina Cheng
- Department of Evolution, Ecology and Behavior, University of Illinois, Urbana-Champaign, IL 61801, USA
| | - Angel G Rivera-Colón
- Department of Evolution, Ecology and Behavior, University of Illinois, Urbana-Champaign, IL 61801, USA
| | - Bushra Fazal Minhas
- Informatics Program, University of Illinois, Urbana-Champaign, IL 61801, USA
| | - Loralee Wilson
- Department of Evolution, Ecology and Behavior, University of Illinois, Urbana-Champaign, IL 61801, USA
| | - Niraj Rayamajhi
- Department of Evolution, Ecology and Behavior, University of Illinois, Urbana-Champaign, IL 61801, USA
| | - Luis Vargas-Chacoff
- Laboratorio de Fisiología de Peces, Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia 5090000, Chile
- Centro Fondap de Investigación de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia 5090000, Chile
- Millennium Institute Biodiversity of Antarctic and Subantarctic Ecosystems (BASE), Universidad Austral de Chile, Valdivia 5090000, Chile
| | - Julian M Catchen
- Department of Evolution, Ecology and Behavior, University of Illinois, Urbana-Champaign, IL 61801, USA
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Raghavan V, Eichele G, Larink O, Karin EL, Söding J. RNA sequencing indicates widespread conservation of circadian clocks in marine zooplankton. NAR Genom Bioinform 2023; 5:lqad007. [PMID: 36814456 PMCID: PMC9939569 DOI: 10.1093/nargab/lqad007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 12/19/2022] [Accepted: 01/06/2023] [Indexed: 02/04/2023] Open
Abstract
Zooplankton are important eukaryotic constituents of marine ecosystems characterized by limited motility in the water. These metazoans predominantly occupy intermediate trophic levels and energetically link primary producers to higher trophic levels. Through processes including diel vertical migration (DVM) and production of sinking pellets they also contribute to the biological carbon pump which regulates atmospheric CO2 levels. Despite their prominent role in marine ecosystems, and perhaps, because of their staggering diversity, much remains to be discovered about zooplankton biology. In particular, the circadian clock, which is known to affect important processes such as DVM has been characterized only in a handful of zooplankton species. We present annotated de novo assembled transcriptomes from a diverse, representative cohort of 17 marine zooplankton representing six phyla and eight classes. These transcriptomes represent the first sequencing data for a number of these species. Subsequently, using translated proteomes derived from this data, we demonstrate in silico the presence of orthologs to most core circadian clock proteins from model metazoans in all sequenced species. Our findings, bolstered by sequence searches against publicly available data, indicate that the molecular machinery underpinning endogenous circadian clocks is widespread and potentially well conserved across marine zooplankton taxa.
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Affiliation(s)
| | | | - Otto Larink
- Evolutionary Biology, Zoological Institute, Technical University Braunschweig, Spielmannstraße 7, 38106, Braunschweig, Germany
| | - Eli Levy Karin
- Quantitative and Computational Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
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Häfker NS, Andreatta G, Manzotti A, Falciatore A, Raible F, Tessmar-Raible K. Rhythms and Clocks in Marine Organisms. ANNUAL REVIEW OF MARINE SCIENCE 2023; 15:509-538. [PMID: 36028229 DOI: 10.1146/annurev-marine-030422-113038] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The regular movements of waves and tides are obvious representations of the oceans' rhythmicity. But the rhythms of marine life span across ecological niches and timescales, including short (in the range of hours) and long (in the range of days and months) periods. These rhythms regulate the physiology and behavior of individuals, as well as their interactions with each other and with the environment. This review highlights examples of rhythmicity in marine animals and algae that represent important groups of marine life across different habitats. The examples cover ecologically highly relevant species and a growing number of laboratory model systems that are used to disentangle key mechanistic principles. The review introduces fundamental concepts of chronobiology, such as the distinction between rhythmic and endogenous oscillator-driven processes. It also addresses the relevance of studying diverse rhythms and oscillators, as well as their interconnection, for making better predictions of how species will respond to environmental perturbations, including climate change. As the review aims to address scientists from the diverse fields of marine biology, ecology, and molecular chronobiology, all of which have their own scientific terms, we provide definitions of key terms throughout the article.
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Affiliation(s)
- N Sören Häfker
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria; ,
- Research Platform "Rhythms of Life," University of Vienna, Vienna BioCenter, Vienna, Austria
| | - Gabriele Andreatta
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria; ,
- Research Platform "Rhythms of Life," University of Vienna, Vienna BioCenter, Vienna, Austria
| | - Alessandro Manzotti
- Laboratoire de Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, UMR 7141, CNRS, Sorbonne Université, Institut de Biologie Physico-Chimique, Paris, France;
| | - Angela Falciatore
- Laboratoire de Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, UMR 7141, CNRS, Sorbonne Université, Institut de Biologie Physico-Chimique, Paris, France;
| | - Florian Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria; ,
- Research Platform "Rhythms of Life," University of Vienna, Vienna BioCenter, Vienna, Austria
| | - Kristin Tessmar-Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria; ,
- Research Platform "Rhythms of Life," University of Vienna, Vienna BioCenter, Vienna, Austria
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
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Häfker NS, Connan-McGinty S, Hobbs L, McKee D, Cohen JH, Last KS. Animal behavior is central in shaping the realized diel light niche. Commun Biol 2022; 5:562. [PMID: 35676530 PMCID: PMC9177748 DOI: 10.1038/s42003-022-03472-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 05/10/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractAnimal behavior in space and time is structured by the perceived day/night cycle. However, this is modified by the animals’ own movement within its habitat, creating a realized diel light niche (RDLN). To understand the RDLN, we investigated the light as experienced by zooplankton undergoing synchronized diel vertical migration (DVM) in an Arctic fjord around the spring equinox. We reveal a highly dampened light cycle with diel changes being about two orders of magnitude smaller compared to the surface or a static depth. The RDLN is further characterized by unique wavelength-specific irradiance cycles. We discuss the relevance of RDLNs for animal adaptations and interactions, as well as implications for circadian clock entrainment in the wild and laboratory.
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