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Drakopoulou I, Protopapa M, Tsangaris C, Zervoudaki S. Mesozooplankton production and respiration across a trophic gradient in a coastal Eastern Mediterranean ecosystem. MARINE ENVIRONMENTAL RESEARCH 2024; 198:106551. [PMID: 38776724 DOI: 10.1016/j.marenvres.2024.106551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/30/2024] [Accepted: 05/10/2024] [Indexed: 05/25/2024]
Abstract
The Inner Saronikos Gulf has served as an area of continuous environmental monitoring for many decades, primarily due to the operation of primary and secondary sewage treatment facilities of the Psyttalia Waste Water Treatment Plant (WWTP). In this groundbreaking study within the region, we conducted measurements of biochemical indices related to respiration (referred to as spETS) and growth (referred to as spAARS) of mesozooplankton. These measurements were then correlated with both biological and environmental data. The ecological quality of the inner Saronikos Gulf was ameliorated moving away from the sewage outfall and thus mesozooplankton sampling encompassed various sites located across a trophic gradient from the WWTP during different seasons (May, September, November 2017, and January 2018). Our observations revealed seasonal variations in both zooplankton abundance and composition, alongside spatial disparities in environmental data. In terms of biochemical data, we observed significant seasonal fluctuations in spETS and R respiration values. Notably, the lowest respiration R value (0.22 mg C m⁻³ d⁻1) was recorded in May, while the highest (4.74 mg C m⁻³ d⁻1) was observed in September. Nevertheless, the variations in spETS and spAARS values among different sites did not demonstrate statistically significant differences. Furthermore, the values of these indices (spETS and spAARS) exhibit a positive correlation with temperature and mesozooplankton biomass at a significance level of 0.01. Lastly, it is noteworthy that phytoplankton production, measured in terms of carbon content (mg C m⁻2), appeared to adequately meet the carbon requirements of the zooplankton throughout all the examined months.
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Affiliation(s)
- I Drakopoulou
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, 19013, Athens, Greece.
| | - M Protopapa
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, 19013, Athens, Greece
| | - C Tsangaris
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, 19013, Athens, Greece
| | - S Zervoudaki
- Hellenic Centre for Marine Research, Institute of Oceanography, P.O. Box 712, 19013, Athens, Greece
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Abstract
Cyclic GMP-AMP synthase, cGAS, converts ATP and GTP into a cyclic dinucleotide second messenger, cyclic GMP-AMP or cGAMP, through its enzymatic, nucleotidyl transferase (NTase) activity. Although many methods are available to directly measure cGAMP production, these assays often have high cost of implementation and/or experimental limitations. This chapter details how to implement an alternative approach that is relatively inexpensive, accurate and medium-throughput. The assay measures cGAS NTase activity by quantifying pyrophosphate production, a byproduct of the cGAS reaction. A coupling enzyme, pyrophosphatase, catalyzes the hydrolysis of pyrophosphate into inorganic phosphate, which enables facile detection of cGAS activity through conventional phosphomolybdate-malachite green absorbance methodology. This method is amenable for conventional steady-state kinetic measurements as well as high-throughput compound screening.
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Affiliation(s)
- Richard Hooy
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
| | - Jungsan Sohn
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
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Yebra L, Kobari T, Sastri AR, Gusmão F, Hernández-León S. Advances in Biochemical Indices of Zooplankton Production. ADVANCES IN MARINE BIOLOGY 2016; 76:157-240. [PMID: 28065295 DOI: 10.1016/bs.amb.2016.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Several new approaches for measuring zooplankton growth and production rates have been developed since the publication of the ICES (International Council for the Exploration of the Sea) Zooplankton Methodology Manual (Harris et al., 2000). In this review, we summarize the advances in biochemical methods made in recent years. Our approach explores the rationale behind each method, the design of calibration experiments, the advantages and limitations of each method and their suitability as proxies for in situ rates of zooplankton community growth and production. We also provide detailed protocols for the existing methods and information relevant to scientists wanting to apply, calibrate or develop these biochemical indices for zooplankton production.
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Affiliation(s)
- L Yebra
- Instituto Español de Oceanografía, Centro Oceanográfico de Málaga, Fuengirola, Málaga, Spain.
| | - T Kobari
- Aquatic Sciences, Faculty of Fisheries, Kagoshima University, Kagoshima, Japan
| | - A R Sastri
- Ocean Networks Canada, University of Victoria, Victoria, BC, Canada; Department of Biology, University of Victoria, Victoria, BC, Canada
| | - F Gusmão
- Federal University of São Paulo, Santos, Brazil
| | - S Hernández-León
- Instituto de Oceanografía y Cambio Global, Universidad de Las Palmas de Gran Canaria, Telde, Gran Canaria, Spain
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McKinnon AD, Doyle J, Duggan S, Logan M, Lønborg C, Brinkman R. Zooplankton Growth, Respiration and Grazing on the Australian Margins of the Tropical Indian and Pacific Oceans. PLoS One 2015; 10:e0140012. [PMID: 26469275 PMCID: PMC4607465 DOI: 10.1371/journal.pone.0140012] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/21/2015] [Indexed: 11/30/2022] Open
Abstract
The specific activity of aminoacyl-tRNA synthetases (spAARS), an index of growth rate, and of the electron transport system (spETS), an index of respiration, was measured in three size fractions (73–150 μm, >150 μm and >350 μm) of zooplankton during five cruises to tropical coastal waters of the Kimberley coast (North West Australia) and four cruises to waters of the Great Barrier Reef (GBR; North East Australia). The N-specific biomass of plankton was 3–4-fold higher in the Kimberley than on the GBR in all 3 size classes: Kimberley 1.27, 3.63, 1.94 mg m-3; GBR 0.36, 0.88 and 0.58 mg m-3 in the 73–150 μm, >150 μm and >350 μm size classes, respectively. Similarly, spAARS activity in the Kimberley was greater than that of the GBR: 88.4, 132.2, and 147.6 nmol PPi hr-1 mg protein -1 in the Kimberley compared with 71.7, 82.0 and 83.8 nmol PPi hr-1 mg protein -1 in the GBR, for the 73–150 μm, >150 μm and >350 μm size classes, respectively. Specific ETS activity showed similar differences in scale between the two coasts: 184.6, 148.8 and 92.2 μL O2 hr-1 mg protein-1 in the Kimberley, against 86.5, 88.3 and 71.3 μL O2 hr-1 mg protein-1 in the GBR. On the basis of these measurements, we calculated that >150 μm zooplankton grazing accounted for 7% of primary production in the Kimberley and 8% in GBR waters. Area-specific respiration by >73 μm zooplankton was 7-fold higher in the Kimberley than on the GBR and production by >150 μm zooplankton was of the order of 278 mg C m-2 d-1 in the Kimberley and 42 mg C m-2 d-1 on the GBR. We hypothesize that the much stronger physical forcing on the North West shelf is the principal driver of higher rates in the west than in the east of the continent.
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Affiliation(s)
- A. David McKinnon
- Australian Institute of Marine Science, P.M.B. No. 3, Townsville M.C. 4810, Queensland, Australia
- The Western Australian Marine Science Institution, Perth, Western Australia, Australia
- School of Marine and Tropical Biology, James Cook University, Townsville 4810, Queensland, Australia
- * E-mail:
| | - Jason Doyle
- Australian Institute of Marine Science, P.M.B. No. 3, Townsville M.C. 4810, Queensland, Australia
| | - Samantha Duggan
- Australian Institute of Marine Science, P.M.B. No. 3, Townsville M.C. 4810, Queensland, Australia
| | - Murray Logan
- Australian Institute of Marine Science, P.M.B. No. 3, Townsville M.C. 4810, Queensland, Australia
| | - Christian Lønborg
- Australian Institute of Marine Science, P.M.B. No. 3, Townsville M.C. 4810, Queensland, Australia
| | - Richard Brinkman
- Australian Institute of Marine Science, P.M.B. No. 3, Townsville M.C. 4810, Queensland, Australia
- The Western Australian Marine Science Institution, Perth, Western Australia, Australia
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Cassandrini D, Cilio MR, Bianchi M, Doimo M, Balestri M, Tessa A, Rizza T, Sartori G, Meschini MC, Nesti C, Tozzi G, Petruzzella V, Piemonte F, Bisceglia L, Bruno C, Dionisi-Vici C, D'Amico A, Fattori F, Carrozzo R, Salviati L, Santorelli FM, Bertini E. Pontocerebellar hypoplasia type 6 caused by mutations in RARS2: definition of the clinical spectrum and molecular findings in five patients. J Inherit Metab Dis 2013; 36:43-53. [PMID: 22569581 DOI: 10.1007/s10545-012-9487-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 03/26/2012] [Accepted: 04/05/2012] [Indexed: 11/27/2022]
Abstract
Recessive mutations in the mitochondrial arginyl-transfer RNA synthetase (RARS2) gene have been associated with early onset encephalopathy with signs of oxidative phosphorylation defects classified as pontocerebellar hypoplasia 6. We describe clinical, neuroimaging and molecular features on five patients from three unrelated families who displayed mutations in RARS2. All patients rapidly developed a neonatal or early-infantile epileptic encephalopathy with intractable seizures. The long-term follow-up revealed a virtual absence of psychomotor development, progressive microcephaly, and feeding difficulties. Mitochondrial respiratory chain enzymes in muscle and fibroblasts were normal in two. Blood and CSF lactate was abnormally elevated in all five patients at early stages while appearing only occasionally abnormal with the progression of the disease. Cerebellar vermis hypoplasia with normal aspect of the cerebral and cerebellar hemispheres appeared within the first months of life at brain MRI. In three patients follow-up neuroimaging revealed a progressive pontocerebellar and cerebral cortical atrophy. Molecular investigations of RARS2 disclosed the c.25A>G/p.I9V and the c.1586+3A>T in family A, the c.734G>A/p.R245Q and the c.1406G>A/p.R469H in family B, and the c.721T>A/p.W241R and c.35A>G/p.Q12R in family C. Functional complementation studies in Saccharomyces cerevisiae showed that mutation MSR1-R531H (equivalent to human p.R469H) abolished respiration whereas the MSR1-R306Q strain (corresponding to p.R245Q) displayed a reduced growth on non-fermentable YPG medium. Although mutations functionally disrupted yeast we found a relatively well preserved arginine aminoacylation of mitochondrial tRNA. Clinical and neuroimaging findings are important clues to raise suspicion and to reach diagnostic accuracy for RARS2 mutations considering that biochemical abnormalities may be absent in muscle biopsy.
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Direct localization and quantitation of aminoacyl-tRNA synthetase activity in polyacrylamide gel. Anal Biochem 1985; 149:474-9. [PMID: 2416242 DOI: 10.1016/0003-2697(85)90601-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A simple procedure for the direct localization and quantitation of aminoacyl-tRNA synthetase activity in polyacrylamide gel is described. The method is based on the white precipitation of Ca-PPi. The white bands of the precipitated calcium salt are clearly visible when viewed against a dark background and can be photographed or scanned.
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