Phenotypic and proteomic responses of Crassostrea gigas to changing temperature and pH during early development Ewan Harney
1, Artigaud, S.1, Miner, P. 2, Le Souchu, P. 2, Corporeau, C.2, Essid, H.1, Pichereau, V.1 &
Nunes,
1 F.
[email protected] Laboratoire des Sciences de l'Environnement Marin (LEMAR) UMR-CNRS/UBO/IRD 6539 1Institut Universitaire Européen de la Mer, 29280 Plouzané, France 2Ifremer, Centre Bretagne Z.I. Pointe du Diable, 29280, Plouzané, France
How will climate change affect marine molluscs? Elevated atmospheric pCO2 affects marine environments via rising sea-surface temperatures and reduced pH. Calcifying molluscs may be at risk due to increasing energetic costs of biomineralisation. We investigated proteomic and phenotypic responses of the pacific oyster Crassostrea gigas during early development (40 hours) under elevated temperature (2 °C), reduced pH (0.2 units), and the interaction of both.
Experimental protocol
C. gigas larvae were reared at high density in open flow tanks. After 40 hours, larvae were recovered in ethanol/PBS for phenotypic analysis (size measurements + birefringence in polarised light), and approximately 160,000 larvae were recovered for protein analysis with 2 dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometry (MS/MS).
Results: Phenotype
Results: Proteomics pI
1 2
7
Temp. (°C)
6
4
5
9
8
MW 10
20
11
12
7.9
pH (units)
Size N = 558
Proteins responding to reduced pH
8.1
ATP synthase Matrilin-2 Severin Actin-2 Severin Vitellogenin-6 Shell matrix protein
Birefringence N= 515
↓ ↓ ↓ ↓ ↓ ↑ ↑
at both temps at 20 °C at 20 °C at 22 °C at 22 °C at 22 °C at 22 °C
Normalised expression values
22
3
Proteins responding to increased Temp PDI2 Universal Stress Protein Grp78 Severin
↑ ↓ ↑ ↑
at pH 7.9 at pH 7.9 at pH 8.1 at pH 8.1
Proteins responding to reduced pH + increased Temp
pH (units) & Temperature (°C)
Significant interaction: pH x Temp
Matrilin-2 ATP synthase GAPDH SOD Vitellogenin-6 Universal Stress Protein
pH (units) & Temperature (°C)
Significant factor: Temp
↓ ↓ ↓ ↑ ↑ ↓
↓ pH and ↑ Temperature together can result in unexpected protein responses
Haliotis tuberculata
Transcriptional versus translational changes?
Venerupis philippanarum
Whole transcriptome sequencing of larvae under these conditions can provide further insight into how marine molluscs deal with environmental stress
© www.aphotomarine.com
How do species vary in their responses?
Pecten maximus © www.aphotomarine.com
Crassostrea gigas © David Monniaux
A phylogenomic comparison across 4 mollusc species can help to identify common and divergent mechanisms within the phylum
