梅氏新贝尼登虫膜联蛋白B1基因序列分析及应激表达分析

Sequence analysis and stress- related changes of the annexin B1 gene in Neobenedenia melleni

膜联蛋白(Annexins,ANX)是一类Ca^(2+)依赖性磷脂结合蛋白多基因家族,参与生物膜修复、Ca^(2+)调节、信号传导、膜泡运输以及细胞增殖等过程,部分成员其mRNA和蛋白表达与发育和环境变化紧密相关。研究采用生物信息学方法鉴定了梅氏新贝尼登虫anxb1(Neobenedenia melleni anxb1,nmanxb1)的序列特征,随后采用RT-qPCR技术确定其mRNA表达与发育和环境(温度和盐度)变化相关性。研究结果表明,NmANXB1具有4个由α-螺旋组成的重复单元,其中3个典型Ⅱ型Ca^(2+)结合位点、6个Ⅲ型Ca^(2+)结合位点,以及1个KGD基序。氨基酸序列的系统进化树分析揭示,nmanxb1与其他B族蠕虫类寄生虫anx共成一簇。RT-qPCR结果显示,nmanxb1 mRNA主要在虫卵中表达。低温和高温应激下虫卵nmanxb1 mRNA表达量显著上调;高温和低盐应激时成虫中的表达量也显著上升。以上结果揭示,NmANXB1可能参与梅氏新贝尼登虫的发育和环境应激适应过程。

Annexins（ ANX） are a multigene family of Ca^（2＋） -dependent phospholipid binding proteins,which are involved in the processes,such as membrane repair,ion channel regulation,signal transduction,vesicular transport and cell proliferation. Some anxs are expressed in the growth and environment（ thermal and salinity）-dependent manner. In this study,bioinformatic approaches were used for sequence analysis of Neobenedenia melleni anxb1（ nmanxb1）. And RT-qPCR was used to detect the mRNA expressions of nmanxb1 responding to the developmental and environmental changes. The results revealed that NmANXB1 was consist of 4 similar repeats made up of α helices,which contained 3 type II Ca^（2＋） binding sites,6 type Ⅲ Ca^（2＋） binding sites,and a KGD motif. Phylogenetic analysis of the amino acid sequences of some anxs showed that nmanxb1 grouped with other the parasitic helminth anxs belonging to group B. The results of RT-q PCR suggested that nmanxb1 mRNA was mainly expressed in the egg. Thermal stress（ cold or hyperthermal stress） caused obviously increased nmanxb1 mRNA expressions in the egg,and hyperthermal and low salinity strss elevated significantly its expressions in the adult. It suggests that nmanxb1 may be involved in development and adaptation to adverse environmental conditions.