Relative gene expression of genes coding for proteins potentially involved in the construction of the prismatic layer (<i>KRMP 7, mantle protein 10, shematrin 9, MPN88, fibronectin 1)</i> the nacreous layer (<i>MSI60, Pif 177, pearlin, linkine)</i> and both the prismatic and the nacreous layers (<i>shematrin 8, nacrein)</i> following 2 months of exposure to 3 temperatures (21°C, 25°C and 28°C) and 2 microalgal concentrations 800 cell mL⁻¹ for low food (LF) (light grey) and 15 000 cell mL⁻¹ for high food (HF) (dark grey).

<p>The results of two measures performed on a pool of 5 pearl oysters are shown for each condition. Statistical differences between temperatures are indicated by a letter.</p

Set of forward and reverse primers used for the gene expression analysis.

<p>Set of forward and reverse primers used for the gene expression analysis.</p

Spearman’s coefficient correlation rho between relative matrix gene expression and SDR.

<p>Correlations were significant (in bold) at the 0.05 level when r<0.28 or >–0.28 (n = 49).</p

Shell deposit rate (µm.d⁻¹) on the ventral side of the shell according to temperature and food concentrations over the two month experiment.

<p>Three temperatures (21, 25 and 28°C) and two microalgal concentrations (800 cell mL⁻¹: light grey and 15000 cell mL⁻¹: darkgrey) were tested. The five homogeneous groups identified by the Tukey post-hoc test (a, b, c and d) are indicated (means and standard error, n = 10).</p

Significance level of Scheirer-Ray–Hare (SHR) non-parametric ANOVA of calcifying genes expression level according to food and temperature levels.

<p>Significance level of Scheirer-Ray–Hare (SHR) non-parametric ANOVA of calcifying genes expression level according to food and temperature levels.</p

Regulation pattern of genes according to temperature (T), food (F) and shell deposition rate (SDR).

<p>Regulation pattern of genes according to temperature (T), food (F) and shell deposition rate (SDR).</p

Section of a valve of a <i>P. margaritifera</i> shell.

<p>(a) dorso-ventral side showing the transition areas between nacreous and prismatic layers. (b) dorsal part; (c) ventral part; (d) central part; (e) detail of ventral part. (1) prismatic calcite; (2) aragonite tablets. The red arrows indicate the calcein mark.</p