Effect of temperature on gene expression in the pearl oyster Pinctada fucata

In this study, we examined the effect of elevated temperature on the expression patterns of genes, i.e., nacrein, irr, n16, n19, and hsp70 in the pearl oyster Pinctada fucata. The experiment was carried out at 4 temperatures, i.e., 20A degrees C (ambient, control), 24, 28A degrees C, and 32A degrees C. The expression levels of target genes in P. fucata were assayed at 0, 6, 24, 48, and 96 h via real-time polymerase chain reaction. Results showed that the expression levels of nacrein and irr had no significant variations among different time points below 28A degrees C, but significantly increased over time at 32A degrees C. The expression levels of n16 and n19 did not change markedly at 20A degrees C. The former increased significantly at 6 h and 24 h while the latter substantially decreased during 6-96 h at 24, 28 and 32A degrees C. Among different temperatures, the level of n16 was significantly lower at 20A degrees C than at other temperatures during 6-96 h, and the level of n19 significantly varied among different temperatures at 48 h and 96 h. The expression level of hsp70 was significantly higher at 32A degrees C than at 20, 24 and 28A degrees C at 24 h. These results demonstrated that elevated temperature impacted the physiological processes of P. fucata and potentially influenced its adaptability to thermal stress.