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Payton L, Last KS, Grigor J, Noirot C, Hüppe L, Conway DVP, Dannemeyer M, Wilcockson D, Meyer B. Revealing the profound influence of diapause on gene expression: Insights from the annual transcriptome of the copepod Calanus finmarchicus. Mol Ecol 2024; 33:e17425. [PMID: 38847383 DOI: 10.1111/mec.17425] [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: 03/29/2024] [Revised: 05/03/2024] [Accepted: 05/17/2024] [Indexed: 06/27/2024]
Abstract
Annual rhythms are observed in living organisms with numerous ecological implications. In the zooplanktonic copepod Calanus finmarchicus, such rhythms are crucial regarding its phenology, body lipid accumulation, and global carbon storage. Climate change drives annual biological rhythms out of phase with the prevailing environmental conditions with yet unknown but potentially catastrophic consequences. However, the molecular dynamics underlying phenology are still poorly described. In a rhythmic analysis of C. finmarchicus annual gene expression, results reveal that more than 90% of the transcriptome shows significant annual rhythms, with abrupt and dramatic upheaval between the active and diapause life cycle states. This work explores the implication of the circadian clock in the annual timing, which may control epigenetic mechanisms to profoundly modulate gene expression in response to calendar time. Results also suggest an increased light sensitivity during diapause that would ensure the photoperiodic entrainment of the endogenous annual clock.
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Affiliation(s)
- Laura Payton
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
- Section Polar Biological Oceanography, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- CNRS, Univ. Bordeaux, Bordeaux INP, EPOC, UMR 5805, Arcachon, F-33120, France
| | - Kim S Last
- Scottish Association for Marine Science, Oban, Argyll, UK
| | - Jordan Grigor
- Scottish Association for Marine Science, Oban, Argyll, UK
| | - Céline Noirot
- Plateforme Bio-Informatique GenoToul, MIAT, INRAE, UR875 Mathématiques et Informatique Appliquées Toulouse, Castanet-Tolosan, France
| | - Lukas Hüppe
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
- Section Polar Biological Oceanography, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Neurobiology and Genetics, Theodor-Boveri Institute, Biocentre, University of Würzburg, Würzburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB) at the Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - David V P Conway
- Marine Biological Association of the UK, the Laboratory, Plymouth, UK
| | - Mona Dannemeyer
- Section Polar Biological Oceanography, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - David Wilcockson
- Department of Life Sciences, Aberystwyth University, Aberystwyth, UK
| | - Bettina Meyer
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
- Section Polar Biological Oceanography, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB) at the Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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Payton L, Noirot C, Last KS, Grigor J, Hüppe L, Conway DVP, Dannemeyer M, Suin A, Meyer B. Annual transcriptome of a key zooplankton species, the copepod Calanus finmarchicus. Ecol Evol 2022; 12:e8605. [PMID: 35228860 PMCID: PMC8861585 DOI: 10.1002/ece3.8605] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/20/2021] [Accepted: 01/10/2022] [Indexed: 12/13/2022] Open
Abstract
The copepod Calanus finmarchicus (Crustacea, Copepoda) is a key zooplanktonic species with a crucial position in the North Atlantic food web and significant contributor to ocean carbon flux. Like many other high latitude animals, it has evolved a programmed arrested development called diapause to cope with long periods of limited food supply, while growth and reproduction are timed to take advantage of seasonal peaks in primary production. However, anthropogenic warming is inducing changes in the expected timing of phytoplankton blooms, suggesting phenological mismatches with negative consequences for the N. Atlantic ecosystem. While diapause mechanisms are mainly studied in terrestrial arthropods, specifically on laboratory model species, such as the fruit fly Drosophila, the molecular investigations of annual rhythms in wild marine species remain fragmentary. Here we performed a rigorous year-long monthly sampling campaign of C. finmarchicus in a Scottish Loch (UK; 56.45°N, 5.18°W) to generate an annual transcriptome. The mRNA of 36 samples (monthly triplicate of 25 individuals) have been deeply sequenced with an average depth of 137 ± 4 million reads (mean ± SE) per sample, aligned to the reference transcriptome, and filtered. We detail the quality assessment of the datasets and provide a high-quality resource for the investigation of wild annual transcriptomic rhythms (35,357 components) in a key diapausing zooplanktonic species.
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Affiliation(s)
- Laura Payton
- Institute for Chemistry and Biology of the Marine EnvironmentCarl von Ossietzky University of OldenburgOldenburgGermany
- Section Polar Biological OceanographyAlfred Wegener Institute Helmholtz Centre for Polar and Marine ResearchBremerhavenGermany
| | - Céline Noirot
- Plateforme bio‐informatique GenoToulMIATINRAEUR875 Mathématiques et Informatique Appliquées ToulouseCastanet‐TolosanFrance
| | - Kim S. Last
- Scottish Association for Marine ScienceObanUK
| | | | - Lukas Hüppe
- Institute for Chemistry and Biology of the Marine EnvironmentCarl von Ossietzky University of OldenburgOldenburgGermany
- Section Polar Biological OceanographyAlfred Wegener Institute Helmholtz Centre for Polar and Marine ResearchBremerhavenGermany
- Neurobiology and GeneticsTheodor‐Boveri InstituteBiocentreUniversity of WürzburgWürzburgGermany
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB)University of OldenburgOldenburgGermany
| | | | - Mona Dannemeyer
- Section Polar Biological OceanographyAlfred Wegener Institute Helmholtz Centre for Polar and Marine ResearchBremerhavenGermany
| | - Amandine Suin
- Plateforme GénomiqueINRAE US 1426 GeT‐PlaGeCentre INRAE de Toulouse OccitanieCastanet‐TolosanFrance
| | - Bettina Meyer
- Institute for Chemistry and Biology of the Marine EnvironmentCarl von Ossietzky University of OldenburgOldenburgGermany
- Section Polar Biological OceanographyAlfred Wegener Institute Helmholtz Centre for Polar and Marine ResearchBremerhavenGermany
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB)University of OldenburgOldenburgGermany
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3
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Lenz PH, Roncalli V, Cieslak MC, Tarrant AM, Castelfranco AM, Hartline DK. Diapause vs. reproductive programs: transcriptional phenotypes in a keystone copepod. Commun Biol 2021; 4:426. [PMID: 33782539 PMCID: PMC8007741 DOI: 10.1038/s42003-021-01946-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 03/01/2021] [Indexed: 02/01/2023] Open
Abstract
Many arthropods undergo a seasonal dormancy termed "diapause" to optimize timing of reproduction in highly seasonal environments. In the North Atlantic, the copepod Calanus finmarchicus completes one to three generations annually with some individuals maturing into adults, while others interrupt their development to enter diapause. It is unknown which, why and when individuals enter the diapause program. Transcriptomic data from copepods on known programs were analyzed using dimensionality reduction of gene expression and functional analyses to identify program-specific genes and biological processes. These analyses elucidated physiological differences and established protocols that distinguish between programs. Differences in gene expression were associated with maturation of individuals on the reproductive program, while those on the diapause program showed little change over time. Only two of six filters effectively separated copepods by developmental program. The first one included all genes annotated to RNA metabolism and this was confirmed using differential gene expression analysis. The second filter identified 54 differentially expressed genes that were consistently up-regulated in individuals on the diapause program in comparison with those on the reproductive program. Annotated to oogenesis, RNA metabolism and fatty acid biosynthesis, these genes are both indicators for diapause preparation and good candidates for functional studies.
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Affiliation(s)
- Petra H. Lenz
- grid.410445.00000 0001 2188 0957Pacific Biosciences Research Center, University of Hawaiʻi at Mānoa, Honolulu, HI USA
| | - Vittoria Roncalli
- grid.410445.00000 0001 2188 0957Pacific Biosciences Research Center, University of Hawaiʻi at Mānoa, Honolulu, HI USA ,grid.6401.30000 0004 1758 0806Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Matthew C. Cieslak
- grid.410445.00000 0001 2188 0957Pacific Biosciences Research Center, University of Hawaiʻi at Mānoa, Honolulu, HI USA
| | - Ann M. Tarrant
- grid.56466.370000 0004 0504 7510Woods Hole Oceanographic Institution, Woods Hole, MA USA
| | - Ann M. Castelfranco
- grid.410445.00000 0001 2188 0957Pacific Biosciences Research Center, University of Hawaiʻi at Mānoa, Honolulu, HI USA
| | - Daniel K. Hartline
- grid.410445.00000 0001 2188 0957Pacific Biosciences Research Center, University of Hawaiʻi at Mānoa, Honolulu, HI USA
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Xie X, Jiang J, Chen M, Huang M, Jin L, Li X. De novo Transcriptome Assembly of Myllocerinus aurolineatus Voss in Tea Plants. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2021. [DOI: 10.3389/fsufs.2021.631990] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Myllocerinus aurolineatus Voss is a species of the insecta class in the arthropod. In this study, we first observed and identified M. aurolineatus Voss in tea plants in Guizhou, China, where it caused severe quantity and quality losses in tea plants. Knowledge on M. aurolineatus Voss genome is inadequate, especially for biological or functional research. We performed the first transcriptome sequencing by using the Illumina Hiseq™ technique on M. aurolineatus Voss. Over 55.9 million high-quality paired-end reads were generated and assembled into 69,439 unigenes using the Trinity short read software, resulting in a cluster of 1,207 bp of the N50 length. A total of 69,439 genes were predicted by BLAST to known proteins in the NCBI database and were distributed into Gene Ontology (20,190), eukaryotic complete genomes (12,488), and the Kyoto Encyclopedia of Genes and Genomes (3,170). We also identified 96,790 single-nucleotide polymorphisms and 13,121 simple sequence repeats in these unigenes. Our transcriptome data provide a useful resource for future functional studies of M. aurolineatus Voss for dispersal control in tea plants.
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Chen B, Chu TW, Chiu K, Hong MC, Wu TM, Ma JW, Liang CM, Wang WK. Transcriptomic analysis elucidates the molecular processes associated with hydrogen peroxide-induced diapause termination in Artemia-encysted embryos. PLoS One 2021; 16:e0247160. [PMID: 33606769 PMCID: PMC7894940 DOI: 10.1371/journal.pone.0247160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 02/03/2021] [Indexed: 01/06/2023] Open
Abstract
Treatment with hydrogen peroxide (H2O2) raises the hatching rate through the development and diapause termination of Artemia cysts. To comprehend the upstream genetic regulation of diapause termination activated by exterior H2O2 elements, an Illumina RNA-seq analysis was performed to recognize and assess comparative transcript amounts to explore the genetic regulation of H2O2 in starting the diapause termination of cysts in Artemia salina. We examined three groupings treated with no H2O2 (control), 180 μM H2O2 (low) and 1800 μM H2O2 (high). The results showed a total of 114,057 unigenes were identified, 41.22% of which were functionally annotated in at least one particular database. When compared to control group, 34 and 98 differentially expressed genes (DEGs) were upregulated in 180 μM and 1800 μM H2O2 treatments, respectively. On the other hand, 162 and 30 DEGs were downregulated in the 180 μM and 1800 μM H2O2 treatments, respectively. Cluster analysis of DEGs demonstrated significant patterns among these types of 3 groups. GO and KEGG enrichment analysis showed the DEGs involved in the regulation of blood coagulation (GO: 0030193; GO: 0050818), regulation of wound healing (GO:0061041), regulation of hemostasis (GO: 1900046), antigen processing and presentation (KO04612), the Hippo signaling pathway (KO04391), as well as the MAPK signaling pathway (KO04010). This research helped to define the diapause-related transcriptomes of Artemia cysts using RNA-seq technology, which might fill up a gap in the prevailing body of knowledge.
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Affiliation(s)
- Bonien Chen
- Department and Graduate Institute of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan
| | - Tah-Wei Chu
- Department and Graduate Institute of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan
| | - Kuohsun Chiu
- Department and Graduate Institute of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Ming-Chang Hong
- Department and Graduate Institute of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan
| | - Tsung-Meng Wu
- Department of Aquaculture, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Jui-Wen Ma
- Department and Graduate Institute of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan
| | - Chih-Ming Liang
- Department of Environmental Engineering and Science, Feng Chia University, Taichung, Taiwan
| | - Wei-Kuang Wang
- Department of Environmental Engineering and Science, Feng Chia University, Taichung, Taiwan
- * E-mail:
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6
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Berger CA, Steinberg DK, Copley NJ, Tarrant AM. De novo transcriptome assembly of the Southern Ocean copepod Rhincalanus gigas sheds light on developmental changes in gene expression. Mar Genomics 2021; 58:100835. [PMID: 33526377 DOI: 10.1016/j.margen.2021.100835] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/30/2020] [Accepted: 12/30/2020] [Indexed: 11/18/2022]
Abstract
Copepods are small crustaceans that dominate most zooplankton communities in terms of both abundance and biomass. In the polar oceans, a subset of large lipid-storing copepods occupy central positions in the food web because of their important role in linking phytoplankton and microzooplankton with higher trophic levels. In this paper, we generated a high-quality de novo transcriptome for Rhincalanus gigas, the largest-and among the most abundant-of the Southern Ocean copepods. We then conducted transcriptional profiling to characterize the developmental transition between late-stage juveniles and adult females. We found that juvenile R. gigas substantially upregulate lipid synthesis and glycolysis pathways relative to females, as part of a developmental gene expression program that also implicates processes such as muscle growth, chitin formation, and ion transport. This study provides the first transcriptional profile of a developmental transition within Rhincalanus gigas or any endemic Southern Ocean copepod, thereby extending our understanding of copepod molecular physiology.
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Affiliation(s)
- Cory A Berger
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States; MIT-WHOI Joint Program in Oceanography/Applied Ocean Science & Engineering, Cambridge and Woods Hole, MA, USA
| | - Deborah K Steinberg
- Virginia Institute of Marine Science, William & Mary, Gloucester Pt, VA 23062, United States
| | - Nancy J Copley
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
| | - Ann M Tarrant
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States.
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Lipid metabolism in Calanus finmarchicus is sensitive to variations in predation risk and food availability. Sci Rep 2020; 10:22322. [PMID: 33339843 PMCID: PMC7749129 DOI: 10.1038/s41598-020-79165-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 12/03/2020] [Indexed: 11/13/2022] Open
Abstract
Late developmental stages of the marine copepods in the genus Calanus can spend extended periods in a dormant stage (diapause) that is preceded by the accumulation of large lipid stores. We assessed how lipid metabolism during development from the C4 stage to adult is altered in response to predation risk and varying food availability, to ultimately understand more of the metabolic processes during development in Calanus copepods. We used RNA sequencing to assess if perceived predation risk in combination with varied food availability affects expression of genes associated with lipid metabolism and diapause preparation in C. finmarchicus. The lipid metabolism response to predation risk differed depending on food availability, time and life stage. Predation risk caused upregulation of lipid catabolism with high food, and downregulation with low food. Under low food conditions, predation risk disrupted lipid accumulation. The copepods showed no clear signs of diapause preparation, supporting earlier observations of the importance of multiple environmental cues in inducing diapause in C. finmarchicus. This study demonstrates that lipid metabolism is a sensitive endpoint for the interacting environmental effects of predation pressure and food availability. As diapause may be controlled by lipid accumulation, our findings may contribute towards understanding processes that can ultimately influence diapause timing.
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Cieslak MC, Castelfranco AM, Roncalli V, Lenz PH, Hartline DK. t-Distributed Stochastic Neighbor Embedding (t-SNE): A tool for eco-physiological transcriptomic analysis. Mar Genomics 2020; 51:100723. [DOI: 10.1016/j.margen.2019.100723] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 10/20/2019] [Accepted: 11/01/2019] [Indexed: 01/19/2023]
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The β-oxidation pathway is downregulated during diapause termination in Calanus copepods. Sci Rep 2019; 9:16686. [PMID: 31723179 PMCID: PMC6853931 DOI: 10.1038/s41598-019-53032-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 10/28/2019] [Indexed: 12/22/2022] Open
Abstract
Calanus copepods are keystone species in marine ecosystems, mainly due to their high lipid content, which is a nutritious food source for e.g. juvenile fish. Accumulated lipids are catabolized to meet energy requirements during dormancy (diapause), which occurs during the last copepodite stage (C5). The current knowledge of lipid degradation pathways during diapause termination is limited. We characterized changes in lipid fullness and generated transcriptional profiles in C5s during termination of diapause and progression towards adulthood. Lipid fullness of C5s declined linearly during developmental progression, but more β-oxidation genes were upregulated in early C5s compared to late C5s and adults. We identified four possible master regulators of energy metabolism, which all were generally upregulated in early C5s, compared to late C5s and adults. We discovered that one of two enzymes in the carnitine shuttle is absent from the calanoid copepod lineage. Based on the geographical location of the sampling site, the field-samples were initially presumed to consist of C. finmarchicus. However, the identification of C. glacialis in some samples underlines the need for performing molecular analyses to reliably identify Calanus species. Our findings contributes to a better understanding of molecular events occurring during diapause and diapause termination in calanoid copepods.
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Lenz PH, Roncalli V. Diapause within the Context of Life-History Strategies in Calanid Copepods (Calanoida: Crustacea). THE BIOLOGICAL BULLETIN 2019; 237:170-179. [PMID: 31714852 DOI: 10.1086/705160] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Post-embryonic diapause in copepods is an adaptation that allows species in the copepod family Calanidae to thrive in high-latitude environments by transforming a short spring phytoplankton bloom into large numbers of lipid-rich individuals capable of surviving a long period of starvation. The copepods, with their high-energy lipid reservoirs, are a critical food source for higher trophic levels, making the Calanidae a key component of high-latitude marine ecosystems. The physiological ecology of the developmental program remains poorly understood. However, new studies using high-throughput RNA sequencing approaches are giving detailed access to physiological status by generating gene expression profiles for both field-collected and laboratory-incubated individuals. These are beginning to characterize the diapause phenotype, elucidate the transcriptional and physiological progression through the diapause program, and illustrate the effects of organism-environment interactions. This paper reviews gene expression profiling studies on the life cycle and diapause program of Neocalanus flemingeri Miller (1988) that were conducted as part of a long-term observation program in the northern Gulf of Alaska. It summarizes recent findings and relates them to the ecology of this species and to that of other calanids.
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11
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Reynolds JA. Noncoding RNA Regulation of Dormant States in Evolutionarily Diverse Animals. THE BIOLOGICAL BULLETIN 2019; 237:192-209. [PMID: 31714856 DOI: 10.1086/705484] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Dormancy is evolutionarily widespread and can take many forms, including diapause, dauer formation, estivation, and hibernation. Each type of dormancy is characterized by distinct features; but accumulating evidence suggests that each is regulated by some common processes, often referred to as a common "toolkit" of regulatory mechanisms, that likely include noncoding RNAs that regulate gene expression. Noncoding RNAs, especially microRNAs, are well-known regulators of biological processes associated with numerous dormancy-related processes, including cell cycle progression, cell growth and proliferation, developmental timing, metabolism, and environmental stress tolerance. This review provides a summary of our current understanding of noncoding RNAs and their involvement in regulating dormancy.
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Skottene E, Tarrant AM, Olsen AJ, Altin D, Hansen BH, Choquet M, Olsen RE, Jenssen BM. A Crude Awakening: Effects of Crude Oil on Lipid Metabolism in Calanoid Copepods Terminating Diapause. THE BIOLOGICAL BULLETIN 2019; 237:90-110. [PMID: 31714858 DOI: 10.1086/705234] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Calanus finmarchicus and Calanus glacialis are keystone zooplankton species in North Atlantic and Arctic marine ecosystems because they form a link in the trophic transfer of nutritious lipids from phytoplankton to predators on higher trophic levels. These calanoid copepods spend several months of the year in deep waters in a dormant state called diapause, after which they emerge in surface waters to feed and reproduce during the spring phytoplankton bloom. Disruption of diapause timing could have dramatic consequences for marine ecosystems. In the present study, Calanus C5 copepodites were collected in a Norwegian fjord during diapause and were subsequently experimentally exposed to the water-soluble fraction of a naphthenic North Sea crude oil during diapause termination. The copepods were sampled repeatedly while progressing toward adulthood and were analyzed for utilization of lipid stores and for differential expression of genes involved in lipid metabolism. Our results indicate that water-soluble fraction exposure led to a temporary pause in lipid catabolism, suggested by (i) slower utilization of lipid stores in water-soluble fraction-exposed C5 copepodites and (ii) more genes in the β-oxidation pathway being downregulated in water-soluble fraction-exposed C5 copepodites than in the control C5 copepodites. Because lipid content and/or composition may be an important trigger for termination of diapause, our results imply that the timing of diapause termination and subsequent migration to the surface may be delayed if copepods are exposed to oil pollution during diapause or diapause termination. This delay could have detrimental effects on ecosystem dynamics.
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Rowarth NM, MacRae TH. ArHsp40 and ArHsp40-2 contribute to stress tolerance and longevity in Artemia franciscana, but only ArHsp40 influences diapause entry. ACTA ACUST UNITED AC 2018; 221:jeb.189001. [PMID: 30158133 DOI: 10.1242/jeb.189001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 08/23/2018] [Indexed: 12/14/2022]
Abstract
Embryos of the crustacean Artemia franciscana develop either ovoviviparously or oviparously, yielding swimming larvae (nauplii) or encysted gastrulae (cysts), respectively. Nauplii moult several times and become adults whereas cysts enter diapause, a state of dormancy characterized by exceptionally low metabolism and high stress tolerance. Synthesis of molecular chaperones such as the J-domain proteins ArHsp40 and ArHsp40-2 occurs during embryo development and post-diapause growth of A. franciscana and they influence development and stress tolerance. To further investigate J-domain protein function, ArHsp40 and ArHsp40-2 were each knocked down by RNA interference. Reductions in ArHsp40 and ArHsp40-2 had no effect on adult survival, time to release of cysts and nauplii from females and first-brood size. However, knockdown of both A. franciscana J-domain proteins reduced the longevity and heat tolerance of nauplii, with the loss of ArHsp40 having a greater effect. The knockdown of ArHsp40, but not of ArHsp40-2, caused approximately 50% of cysts to abort diapause entry and hatch without exposure to an exogenous signal such as low temperature and/or desiccation. Cysts lacking ArHsp40 that entered diapause exhibited decreased stress tolerance as did cysts with reduced ArHsp40-2, the latter to a lesser degree. The longevity of nauplii hatching prematurely from cysts was less than for nauplii arising by other means. The results expand our understanding of Hsp40 function in A. franciscana stress tolerance and development, especially during diapause, and they provide the first example of a molecular chaperone that influences diapause entry.
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Affiliation(s)
- Nathan M Rowarth
- Department of Biology, Dalhousie University, Halifax, NS, B3H 4R2 Canada
| | - Thomas H MacRae
- Department of Biology, Dalhousie University, Halifax, NS, B3H 4R2 Canada
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14
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Tollefsen KE, Song Y, Høgåsen T, Øverjordet IB, Altin D, Hansen BH. Mortality and transcriptional effects of inorganic mercury in the marine copepod Calanus finmarchicus. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2017; 80:845-861. [PMID: 28841366 DOI: 10.1080/15287394.2017.1352198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Inorganic mercury (Hg) is highly toxic to organisms including crustaceans and displays multiple toxic modes of action (MoA). The main aim of this investigation was to assess the acute and sublethal toxicity mediated by mercury chloride (HgCl2) in the marine copepod Calanus finmarchicus. A combination of short-term static studies to determine acute toxicity and a transcriptional investigation to characterize the sublethal MoA of HgCl2 were conducted with an in-house continuous culture of C. finmarchicus. Transcriptional changes were determined by a custom 6.6 k C. finmarchicus Agilent oligonucleotide microarray and quantitative RT-PCR analysis. Data demonstrate that HgCl2 produced a concentration- and time-dependent reduction in survival (NOEC48 h = 6.9 μg/L [Hg2+] and LC50 of 279, 73, 48, and 34 µg/L [Hg2+] after 24, 48, 72, and 96 h, respectively) and that exposure to sublethal concentrations of HgCl2 (5 μg/L [Hg2+]) induced differential expression of 98 features (probes) on the microarray. Gene ontology (GO) and toxicological pathway analyses suggested that the main MOA were (1) uncoupling of mitochondrial oxidative phosphorylation (OXPHOS) and ATP production, (2) oxidative stress and macromolecular damage, (3) inactivation of cellular enzymes, (4) induction of cellular apoptosis and autophagocytosis, (5) over-excitation of glutamate receptors (neurotoxicity), (6) disruption of calcium homeostasis and signaling, and (7) modulation of nuclear receptor activity involved in vitamin D receptor signaling. Quantitative RT-PCR analysis verified that oligoarray performed reliably in terms of specificity and response, thus demonstrating that Hg2+ exerts multiple potential MoA in C. finmarchicus.
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Affiliation(s)
- Knut Erik Tollefsen
- a Norwegian Institute for Water Research (NIVA) , Oslo , Norway
- b Faculty of Environmental Sciences and Natural Resource Management , Norwegian University of Life Sciences (NMBU) , Ås , Norway
- c Centre for Environmental Radioactivity , Norwegian University of Life Sciences (NMBU) , Ås , Norway
| | - You Song
- a Norwegian Institute for Water Research (NIVA) , Oslo , Norway
- c Centre for Environmental Radioactivity , Norwegian University of Life Sciences (NMBU) , Ås , Norway
| | - Tore Høgåsen
- a Norwegian Institute for Water Research (NIVA) , Oslo , Norway
| | - Ida Beathe Øverjordet
- d Department of Biology , Norwegian University of Science and Technology (NTNU) , Trondheim , Norway
- e SINTEF Ocean AS, Environmental Technology , Trondheim , Norway
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15
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Baumgartner MF, Tarrant AM. The Physiology and Ecology of Diapause in Marine Copepods. ANNUAL REVIEW OF MARINE SCIENCE 2017; 9:387-411. [PMID: 27814030 DOI: 10.1146/annurev-marine-010816-060505] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Diapause is a type of dormancy that requires preparation, typically precedes the onset of unfavorable conditions, and necessitates a period of arrest before development can proceed. Two ecologically important groups of copepods have incorporated diapausing stages into their life histories. In freshwater, estuarine, and coastal environments, species within the Centropagoidea superfamily can produce resting eggs containing embryos that may be quiescent, diapausing, or in some intermediate state. Resting eggs sink into the sediments, remain viable over months to years, and form a reservoir from which the planktonic population is reestablished. In coastal and oceanic environments, copepods within the Calanidae and Eucalanidae families can enter diapause during late juvenile (copepodid) or adult stages. These copepods accumulate large amounts of lipids before they migrate into deep water and diapause for several months. Through respiration, diapausing copepods may sequester more carbon in the deep ocean than any other biogeochemical process, and changes in diapause phenology associated with climate change (particularly reduction in diapause duration) could have a significant impact not only on regional ecosystems, but on global climate as well.
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Affiliation(s)
- Mark F Baumgartner
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543; ,
| | - Ann M Tarrant
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543; ,
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16
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Mykles DL, Burnett KG, Durica DS, Joyce BL, McCarthy FM, Schmidt CJ, Stillman JH. Resources and Recommendations for Using Transcriptomics to Address Grand Challenges in Comparative Biology. Integr Comp Biol 2016; 56:1183-1191. [PMID: 27639274 PMCID: PMC5146710 DOI: 10.1093/icb/icw083] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
High-throughput RNA sequencing (RNA-seq) technology has become an important tool for studying physiological responses of organisms to changes in their environment. De novo assembly of RNA-seq data has allowed researchers to create a comprehensive catalog of genes expressed in a tissue and to quantify their expression without a complete genome sequence. The contributions from the "Tapping the Power of Crustacean Transcriptomics to Address Grand Challenges in Comparative Biology" symposium in this issue show the successes and limitations of using RNA-seq in the study of crustaceans. In conjunction with the symposium, the Animal Genome to Phenome Research Coordination Network collated comments from participants at the meeting regarding the challenges encountered when using transcriptomics in their research. Input came from novices and experts ranging from graduate students to principal investigators. Many were unaware of the bioinformatics analysis resources currently available on the CyVerse platform. Our analysis of community responses led to three recommendations for advancing the field: (1) integration of genomic and RNA-seq sequence assemblies for crustacean gene annotation and comparative expression; (2) development of methodologies for the functional analysis of genes; and (3) information and training exchange among laboratories for transmission of best practices. The field lacks the methods for manipulating tissue-specific gene expression. The decapod crustacean research community should consider the cherry shrimp, Neocaridina denticulata, as a decapod model for the application of transgenic tools for functional genomics. This would require a multi-investigator effort.
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Affiliation(s)
- Donald L Mykles
- *Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Karen G Burnett
- Grice Marine Laboratory, College of Charleston, Charleston, SC 29412, USA
- Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - David S Durica
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Blake L Joyce
- BIO5 Institute, School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Fiona M McCarthy
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Carl J Schmidt
- Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716
| | - Jonathon H Stillman
- Romberg Tiburon Center for Environmental Studies and Department of Biology, San Francisco State University, Tiburon, CA 94920, USA
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA
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17
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Mykles DL, Burnett KG, Durica DS, Stillman JH. Tapping the Power of Crustacean Transcriptomics to Address Grand Challenges in Comparative Biology: An Introduction to the Symposium. Integr Comp Biol 2016; 56:1047-1054. [PMID: 27591249 DOI: 10.1093/icb/icw116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Crustaceans, and decapods in particular (i.e., crabs, shrimp, and lobsters), are a diverse and ecologically and commercially important group of organisms. Understanding responses to abiotic and biotic factors is critical for developing best practices in aquaculture and assessing the effects of changing environments on the biology of these important animals. A relatively small number of decapod crustacean species have been intensively studied at the molecular level; the availability, experimental tractability, and economic relevance factor into the selection of a particular species as a model. Transcriptomics, using high-throughput next generation sequencing (NGS, coupled with RNA sequencing or RNA-seq) is revolutionizing crustacean biology. The 11 symposium papers in this volume illustrate how RNA-seq is being used to study stress response, molting and limb regeneration, immunity and disease, reproduction and development, neurobiology, and ecology and evolution. This symposium occurred on the 10th anniversary of the symposium, "Genomic and Proteomic Approaches to Crustacean Biology", held at the Society for Integrative and Comparative Biology 2006 meeting. Two participants in the 2006 symposium, the late Paul Gross and David Towle, were recognized as leaders who pioneered the use of molecular techniques that would ultimately foster the transcriptomics research reviewed in this volume. RNA-seq is a powerful tool for hypothesis-driven research, as well as an engine for discovery. It has eclipsed the technologies available in 2006, such as microarrays, expressed sequence tags, and subtractive hybridization screening, as the millions of "reads" from NGS enable researchers to de novo assemble a comprehensive transcriptome without a complete genome sequence. The symposium series concludes with a policy paper that gives an overview of the resources available and makes recommendations for developing better tools for functional annotation and pathway and network analysis in organisms in which the genome is not available or is incomplete.
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Affiliation(s)
- Donald L Mykles
- *Department of Biology, Colorado State University, 1878 Campus, Fort Collins, CO 80523, USA
| | - Karen G Burnett
- Grice Marine Laboratory, College of Charleston, 205 Fort Johnson Rd., Charleston, SC 29412, USA.,Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - David S Durica
- Department of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA
| | - Jonathon H Stillman
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, 3152 Paradise Drive, Tiburon, CA 94920, USA.,Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA
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