摘要软体动物碳酸钙贝壳的形成过程涉及到C a2＋的吸收、转运、贮藏、分泌和沉积等，与钙代谢这一高度受控的复杂生理过程紧密相关。本研究以栉孔扇贝转录组测序结果为基础，通过RACE技术，从栉孔扇贝外套膜中克隆得到钙调素类似蛋白的cDNA序列，全长863 bp ，编码149个氨基酸，相应蛋白质的预测分子量约为17．0 ku ，理论等电点为4．03。钙调素类似蛋白具有4个可能的EF‐hand Ca2＋结合结构域，属于 EF‐hand钙结合蛋白家族，其氨基酸序列与栉孔扇贝钙调素钙调素的相似度为66％。半定量RT‐PCR检测显示，钙调素类似蛋白基因在外套膜中特异性高表达，预示其可能参与贝壳的矿化过程。实时定量PCR检测显示，钙调素类似蛋白基因的表达水平随环境中Ca2＋浓度的升高呈先升后降趋势，表明钙调素类似蛋白与外套膜中的钙代谢过程密切相关；在贝壳缺刻损伤后的再生过程中，钙调素类似蛋白基因表达量显著上升，暗示其积极参与到了贝壳的再生过程中。上述结果为进一步阐明钙调素类似蛋白基因的功能及其在栉孔扇贝生物矿化过程中的作用提供可能的理论依据。
Abstract：T he formation of mollusk shells as products of calcium metabolism is a very complicated process highly controlled by many physiological and biochemical activities .However ,the regulation of calcium me‐tabolism in bivalves is poorly understood .In this study ,a calmodulin‐like protein CaLP was cloned from the mantle tissue of scallop Chlamys f arreri .The full‐length cDNA of CaLP was 863 bp ,including a 450‐bp open reading frame (ORF) ,encoding 149 aa with 17 .0 ku and pI of 4 .03 .CaLP was found to contain four putative EF‐hand domains ,with the ability of Ca2+‐binding ,and 66% identity with the C . f arreri CaM in the amino sequence .The scallop CaLP mRNA was expressed in all tissues tested ,with the maxi‐mal level in the mantle ,a key organ involved in calcium secretion and shell formation ,indicating that CaLP takes an important part in the calcium metabolic process of the scallop .Moreover ,the expression of CaLP gene in the mantle went up and came down along with the elevated Ca2+ concentration ,and then reached a climax with a moderate (30% ) increase in Ca2+ concentration ,indicating that the suitable Ca2+ concentra‐tion accelerated the high expression of CaLP gene ,otherwise ,it inhibited the expression of CaLP gene . The function of CaLP in biomineralization was investigated in a shell notching experiment .It was found that the expression of CaLP was greatly enhanced in the mantle tissue in the notched shells ,implying that CaLP was involved in the shell regeneration .The findings will provide useful information for further stud‐ies on function of CaLP gene as well as the biomineralization process in the scallop .
收稿日期: 2014-11-25
引用本文:
林亚,李世国,谢莉萍,张荣庆. 栉孔扇贝钙调素类似蛋白基因的克隆及其与钙调素基因表达特征的比较分析[J]. , 2014, (11): 692-701.
LIN Ya,LI Shi-guo,XIE Li-ping,ZHANG Rong-qing. Molecular Cloning of Calmodulin-like Protein Gene CaLP and Comparison with Expression Profiles of CaM Gene in Scallop Chlamys f arreri. , 2014, (11): 692-701.
