Transcriptomic response of the Pacific oyster Crassostrea gigas to hypoxia

SUMMARYCalcifying marine invertebrates with complex life cycles are particularly at risk to climate changes as they undergo an abrupt ontogenetic shift during larval metamorphosis. Although our understanding of the larval response to climate changes is rapidly advancing, the proteome plasticity involved in a compensatory response to climate change is still unknown. In this study, we investigated the proteomic response of metamorphosing larvae of the tubeworm Hydroides elegans, challenged with two climate change stressors, ocean acidification (OA; pH 7.6) and hypoxia (HYP; 2.8 mg O 2 l −1 ), and with both combined. Using a twodimensional gel electrophoresis (2-DE)-based approach coupled with mass spectrometry, we found that climate change stressors did not affect metamorphosis except under OA, but altered the larval proteome and phosphorylation status. Metabolism and various stress and calcification-related proteins were downregulated in response to OA. In OA and HYP combined, HYP restored the expression of the calcification-related proteins to the control levels. We speculate that mild HYP stress could compensate for the negative effects of OA. This study also discusses the potential functions of selected proteins that might play important roles in larval acclimation and adaption to climate change.Supplementary material available online at http://jeb.biologists.org/lookup/suppl

Section: Larval Proteome Plasticitysupporting

confidence: 93%

Proteomic response of marine invertebrate larvae to ocean acidification and hypoxia during metamorphosis and calcification

Mukherjee

Wong

Chandramouli

et al. 2013

“…The significant increase in OCR that we saw in the present study suggests that metabolism is increased prior to the low tide, as an anticipated response to the adverse hypoxic conditions occurring during this period in the burrows. The adaptive significance of such a biological rhythm has been discussed for other taxa (MacDougallShackleton et al, 2015), and it has been related to preparatory adjustments in physiology, as proposed in the Pacific oyster (Crassotrea gigas) prior to hypoxia exposure (Sussarellu et al, 2010). An alternative explanation might lead the endogenous cycle to be in phase with the actual dynamics of oxygen availability in the burrow's water, which could be renewed much later than the low tide, depending on its relative position along the intertidal zone.…”

Section: Resultsmentioning

confidence: 99%

Tide-related biological rhythm in the oxygen consumption rate of ghost shrimp (Neotrypaea uncinata Milne Edwards)

Leiva

Niklitschek

Paschke

et al. 2016

The effects of tidal height (high and low), acclimation to laboratory conditions (days in captivity) and oxygen level (hypoxia and normoxia) were evaluated in the oxygen consumption rate (OCR) of the ghost shrimp Neotrypaea uncinata. We evaluated the hypothesis that N. uncinata reduces its OCR during low tide and increases it during high tide, regardless of oxygen level or acclimation. Additionally, the existence of an endogenous rhythm in OCR was explored, and we examined whether it synchronized with tidal, diurnal or semidiurnal cycles. Unexpectedly, high OCRs were observed at low tide, during normoxia, in non-acclimated animals. Results from a second, longer experiment under normoxic conditions suggested the presence of a tide-related metabolic rhythm, a response pattern not yet demonstrated for a burrowing decapod. Although rhythms persisted for only 2 days after capture, their period of 12.8 h closely matched the semidiurnal tidal cycle that ghost shrimp confront inside their burrows.

“…For example, in some studies quoted above, transcriptional Hc expression decreased while at the same time the amount of Hc increased. And Sussarellu et al (Sussarellu et al, 2010) could not infer a global metabolic depression at the transcriptional level in the Pacific oyster. A number of investigators, while strong advocators of -omics approaches, have highlighted the major challenges of knowing what we can take from the data they generate and, in particular, making sense of the transcriptome (Feder and Walser, 2005;Rupert, 2008;Vijay et al, 2013).…”

Section: Challengesmentioning

confidence: 96%

“…Therefore, it is interesting that air exposure induced a response from the largest number of genes, 4420. However, the effect of environmental hypoxia on the C. gigas transcriptome was published 2 years previously (Sussarellu et al, 2010). The authors recorded a hypoxia-induced upregulation of genes associated with antioxidant defence and the respiratory chain compartment.…”

Section: -Omics and Physiological Responses Of Marine Invertebrates Tmentioning

confidence: 99%

“…The authors recorded a hypoxia-induced upregulation of genes associated with antioxidant defence and the respiratory chain compartment. Sussarellu et al (Sussarellu et al, 2010) attributed these upregulations to either hypoxia-induced oxidative stress or an 'anticipatory response for normoxic recovery' (see also Le Moullac et al, 2007). They found that another 1694 genes varied independent of hypoxia.…”

Section: -Omics and Physiological Responses Of Marine Invertebrates Tmentioning

confidence: 99%

See 1 more Smart Citation

What can an ecophysiological approach tell us about the physiological responses of marine invertebrates to hypoxia?

Spicer

2014

Hypoxia (low O 2 ) is a common and natural feature of many marine environments. However, human-induced hypoxia has been on the rise over the past half century and is now recognised as a major problem in the world's seas and oceans. Whilst we have information on how marine invertebrates respond physiologically to hypoxia in the laboratory, we still lack understanding of how they respond to such stress in the wild (now and in the future). Consequently, here the question 'what can an ecophysiological approach tell us about physiological responses of marine invertebrates to hypoxia' is addressed. How marine invertebrates work in the wild when challenged with hypoxia is explored using four case studies centred on different hypoxic environments. The recent integration of the various -omics into ecophysiology is discussed, and a number of advantages of, and challenges to, successful integration are suggested. The case studies and -omic/physiology integration data are used to inform the concluding part of the review, where it is suggested that physiological responses to hypoxia in the wild are not always the same as those predicted from laboratory experiments. This is due to behaviour in the wild modifying responses, and therefore more than one type of 'experimental' approach is essential to reliably determine the actual response. It is also suggested that assuming it is known what a measured response is 'for' can be misleading and that taking parodies of ecophysiology seriously may impede research progress. This review finishes with the suggestion that an -omics approach is, and is becoming, a powerful method of understanding the response of marine invertebrates to environmental hypoxia and may be an ideal way of studying hypoxic responses in the wild. Despite centring on physiological responses to hypoxia, the review hopefully serves as a contribution to the discussion of what (animal) ecophysiology looks like (or should look like) in the 21st century.