脊尾白虾甘露糖结合凝集素(MBL)基因在抗镉胁迫中的生物学功能分析

为研究Cd2+胁迫下脊尾白虾(Exopalaemon carinicauda)甘露糖集合凝集素(MBL)在肝胰腺中表达量的变化特征，本研究利用重金属镉(Cd2+)对脊尾白虾进行96 h急性毒性实验。实验共设置5组Cd2+浓度胁迫(0、0.01、0.0175、0.021和0.0278 mmol/L)，分别在Cd2+胁迫后0、3、6、12、24、48、72和96 h共8个时间点取样。实时荧光定量结果显示，高浓度Cd2+(0.0175、0.021和0.0278 mmol/L)胁迫下，脊尾白虾MBL基因的表达量先呈上升趋势，在72 h达到峰值后随后下降，但各时间点表达量均与对照组存在显著性差异(P<0.01)；Cd2+浓度为0.01 mmol/L时，脊尾白虾MBL基因的表达量整体呈下降趋势。进一步采用RNA技术干扰该基因表达后，发现Cd2+胁迫后的脊尾白虾个体死亡率显著增加。本研究表明，脊尾白虾MBL在应答Cd2+胁迫过程中可对机体起到一定的保护作用。

Biological Functional Analysis of MBL Gene in Resistance to Cadmium Stress in Exopalaemon carinicauda

In order to study the expression profile of mannose-binding lectin (MBL) in response to the stress of heavy metal cadmium (Cd2+) in the ridgetail white prawn, Exopalaemon carinicauda, changes of MBL expression level during 96 h of stress were analyzed in the tissue of hepatopancreas. Five Cd2+ stress concentrations (0, 0.01, 0.0175, 0.021 and 0.0278 mmol/L) were set up in the experiment, and the samples were taken at 8 time points, i.e. 0, 3, 6, 12, 24, 48, 72 and 96 hours after Cd2+ stress. The real-time fluorescence quantitative results showed that under the stress of high concentration of Cd2+ (0.0175, 0.021 and 0.0278 mmol/L), the expression level of MBL gene in the ridgetail white prawn increased first, then decreased after reaching the peak at 72 h. There are significant differences between experimental group and control group at all the stress time points. When the cadmium ion was 0.01 mmol/L, a lower concentration, the expression level of MBL gene in the ridgetail white prawn tends to decrease from the beginning. Further interfering down the expression level of MBL using the RNA technology, it was discovered that the mortality rate of Cd2+ stressed individuals were higher than those of the control group. This study showed that MBL potentially took part in the protection of E. carinicada from Cd2+ stress.