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Rosic N, Delamare-Deboutteville J, Dove S. Heat stress in symbiotic dinoflagellates: Implications on oxidative stress and cellular changes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 944:173916. [PMID: 38866148 DOI: 10.1016/j.scitotenv.2024.173916] [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: 12/30/2023] [Revised: 05/18/2024] [Accepted: 06/08/2024] [Indexed: 06/14/2024]
Abstract
Global warming has been shown to harmfully affect symbiosis between Symbiodiniaceae and other marine invertebrates. When symbiotic dinoflagellates (the genus Breviolum) were in vitro exposed to acute heat stress of +7 °C for a period of 5 days, the results revealed the negative impact on all physiological and other cellular parameters measured. Elevated temperatures resulted in a severe reduction in algal density of up to 9.5-fold, as well as pigment concentrations, indicating the status of the physiological stress and early signs of photo-bleaching. Reactive oxygen species (ROS) were increased in all heated dinoflagellate cells, while the antioxidant-reduced glutathione levels initially dropped on day one but increased under prolonged temperature stress. The cell viability parameters were reduced by 97 % over the heating period, with an increased proportion of apoptotic and necrotic cells. Autofluorescence (AF) for Cy5-PE 660-20 was reduced from 1.7-fold at day 1 to up to 50-fold drop at the end of heating time, indicating that the AF changes were highly sensitive to heat stress and that it could be an extremely sensitive tool for assessing the functionality of algal photosynthetic machinery. The addition of the drug 5-AZA-2'-deoxycytidine (5-AZA), which inhibits DNA methylation processes, was assessed in parallel and contributed to some alterations in algal cellular stress response. The presence of drug 5-AZA combined with the temperature stress had an additional impact on Symbiodiniaceae density and cell complexity, including the AF levels. These variations in cellular stress response under heat stress and compromised DNA methylation conditions may indicate the importance of this epigenetic mechanism for symbiotic dinoflagellate thermal tolerance adaptability over a longer period, which needs further exploration. Consequently, the increased ROS levels and changes in AF signals reported during ongoing heat stress in dinoflagellate cells could be used as early stress biomarkers in these microalgae and potentially other photosynthetic species.
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Affiliation(s)
- Nedeljka Rosic
- Faculty of Health, Southern Cross University, Gold Coast, QLD, Australia; Marine Ecology Research Centre, Southern Cross University, Lismore, NSW, Australia.
| | | | - Sophie Dove
- School of Biological Sciences, The University of Queensland, St. Lucia, Qld, Australia
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Zhou S, Chen T, Fu ES, Zhou T, Shi L, Yan H. A microfluidic microalgae detection system for cellular physiological response based on an object detection algorithm. LAB ON A CHIP 2024; 24:2762-2773. [PMID: 38682283 DOI: 10.1039/d3lc00941f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
The composition of species and the physiological status of microalgal cells serve as significant indicators for monitoring marine environments. Symbiotic with corals, Symbiodiniaceae are more sensitive to the environmental response. However, current methods for evaluating microalgae tend to be population-based indicators that cannot be focused on single-cell level, ignoring potentially heterogeneous cells as well as cell state transitions. In this study, we proposed a microalgal cell detection method based on computer vision and microfluidics, which combined microscopic image processing, microfluidic chip and convolutional neural network to achieve label-free, sheathless, automated and high-throughput microalgae identification and cell state assessment. By optimizing the data import, training process and model architecture, we solved the problem of identifying tiny objects at the micron scale, and the optimized model was able to perform the tasks of cell multi-classification and physiological state assessment with more than 95% mean average precision. We discovered a novel transition state and explored the thermal sensitivity of three clades of Symbiodiniaceae, and discovered the phenomenon of cellular heat shock at high temperatures. The evolution of the physiological state of Symbiodiniaceae cells is very important for directional cell evolution and early warning of coral ecosystem health.
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Affiliation(s)
- Shizheng Zhou
- School of Computer Science and Technology, Hainan University, Haikou 570228, China.
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Tianhui Chen
- School of Computer Science and Technology, Hainan University, Haikou 570228, China.
| | - Edgar S Fu
- Graduate School of Computing and Information Science, University of Pittsburgh, PA 15260, USA
| | - Teng Zhou
- School of Mechanical and Electrical Engineering, Hainan University, Haikou 570228, China
| | - Liuyong Shi
- School of Mechanical and Electrical Engineering, Hainan University, Haikou 570228, China
| | - Hong Yan
- School of Computer Science and Technology, Hainan University, Haikou 570228, China.
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
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Matthews JL, Ueland M, Bartels N, Lawson CA, Lockwood TE, Wu Y, Camp EF. Multi-Chemical Omics Analysis of the Symbiodiniaceae Durusdinium trenchii under Heat Stress. Microorganisms 2024; 12:317. [PMID: 38399721 PMCID: PMC10893086 DOI: 10.3390/microorganisms12020317] [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: 12/31/2023] [Revised: 01/22/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The urgency of responding to climate change for corals necessitates the exploration of innovative methods to swiftly enhance our understanding of crucial processes. In this study, we employ an integrated chemical omics approach, combining elementomics, metabolomics, and volatilomics methodologies to unravel the biochemical pathways associated with the thermal response of the coral symbiont, Symbiodiniaceae Durusdinium trenchii. We outline the complimentary sampling approaches and discuss the standardised data corrections used to allow data integration and comparability. Our findings highlight the efficacy of individual methods in discerning differences in the biochemical response of D. trenchii under both control and stress-inducing temperatures. However, a deeper insight emerges when these methods are integrated, offering a more comprehensive understanding, particularly regarding oxidative stress pathways. Employing correlation network analysis enhanced the interpretation of volatile data, shedding light on the potential metabolic origins of volatiles with undescribed functions and presenting promising candidates for further exploration. Elementomics proves to be less straightforward to integrate, likely due to no net change in elements but rather elements being repurposed across compounds. The independent and integrated data from this study informs future omic profiling studies and recommends candidates for targeted research beyond Symbiodiniaceae biology. This study highlights the pivotal role of omic integration in advancing our knowledge, addressing critical gaps, and guiding future research directions in the context of climate change and coral reef preservation.
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Affiliation(s)
- Jennifer L. Matthews
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Maiken Ueland
- Centre for Forensic Sciences, School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
- Hyphenated Mass Spectrometry Laboratory, School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Natasha Bartels
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Caitlin A. Lawson
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW 2258, Australia
| | - Thomas E. Lockwood
- Hyphenated Mass Spectrometry Laboratory, School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Yida Wu
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Emma F. Camp
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW 2007, Australia
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