Impacts of the combined exposure to seawater acidification and arsenic on the proteome of Crassostrea angulata and Crassostrea gigas

Abstract

Proteomic analysis was performed to compare the effects of Arsenic (As), seawater acidification (Low pH) and the combination of both stressors (Low pH + As) on Crassostrea angulata and Crassostrea gigas juveniles in the context of global environmental change. This study aimed to elucidate if two closely related Crassostrea species respond similarly to these environmental stressors, considering both single and combined exposures, to infer if the simultaneous exposure to both stressors induced a differentiated response. Identification of the most important differentially expressed proteins between conditions revealed marked differences in the response of each species towards single and combined exposures, evidencing species-related differences towards each experimental condition. Moreover, protein alterations observed in the combined exposure (Low pH + As) were substantially different from those observed in single exposures. Identified proteins and their putative biological functions revealed an array of modes of action in each condition. Among the most important, those involved in cellular structure (Actin, Atlastin, Severin, Gelsolin, Coronin) and extracellular matrix modulation (Ependymin, Tight junction ZO-1, Neprilysin) were strongly regulated, although in different exposure conditions and species. Data also revealed differences regarding metabolic modulation capacity (ATP β, Enolase, Aconitate hydratase) and oxidative stress response (Aldehyde dehydrogenase, Lactoylglutathione, Retinal dehydrogenase) of each species, which also depended on single or combined exposures, illustrating a different response capacity of both oyster species to the presence of multiple stressors. Interestingly, alterations of piRNA abundance in C. angulata suggested genome reconfiguration in response to multiple stressors, likely an important mode of action related to adaptive evolution mechanisms previously unknown to oyster species, which requires further investigation. The present findings provide a deeper insight into the complexity of C. angulata and C. gigas responses to environmental stress at the proteome level, evidencing different capacities to endure abiotic changes, with relevance regarding the ecophysiological fitness of each species and competitive advantages in a changing environment.

Differential DNA methylation in Pacific oyster reproductive tissue in response to ocean acidification

“…Several genes with DML and enriched GOterms have links to stress response and gonad development. In C. gigas , expression of cell cycle regulators kinesin-like protein KIF23 and serine-protein kinase ATM changes in response to immune challenge or low pH and arsenic exposure, respectively [ 38 , 39 ]. Kinesin-like proteins have higher expression in mature C. gigas gonads [ 33 ], and serine-protein kinase ATM is involved in razor clam Sinonovacula constricta oogenesis [ 40 ].…”

“…Therefore, it’s possible cytoplasmic aconitate hydratase may regulate energy metabolism during oogenesis as well. Evidence of cytoplasmic aconitate hydratase abundance changing in response to low pH has been documented in C. gigas , which implies that low pH alters energy metabolism [ 39 ]. Energy metabolism would be important to regulate in developing oocytes.…”

The effect of temperature on Triclosan and Lead exposed mussels

“…2016; Freitas et al, 2017;Lannig et al, 2010;Matoo et al, 2013;Moreira et al, 2018;Munari et al, 2018). In the scenario of global warming, aquatic organisms are subjected to water temperature fluctuations that may alter their thermal tolerances.…”

Differential DNA methylation in Pacific oyster reproductive tissue in response to ocean acidification

“…Therefore, it’s possible cytoplasmic aconitate hydratase may regulate energy metabolism during oogenesis as well. Evidence of cytoplasmic aconitate hydratase abundance changing in response to low pH has been documented in C. gigas , which implies that low pH alters energy metabolism [54]. Energy metabolism would be important to regulate in developing oocytes.…”

“…Several genes with DML and enriched GOterms have links to stress response and gonad development. In C. gigas , expression of cell cycle regulators kinesin-like protein KIF23 and serine-protein kinase ATM changes in response to immune challenge or low pH and arsenic exposure, respectively [37, 38]. Kinesin-like proteins have higher expression in mature C. gigas gonads [32], and serine-protein kinase ATM is involved in razor clam Sinonovacula constricta oogenesis [39].…”