Cholinesterases are key enzymes in central and peripheral cholinergic nerve system functioning on nerve impulse transmission in animals. Though cholinesterases have been identified in most vertebrates, the knowledge about the variable numbers and multiple functions of the genes is still quite meagre in invertebrates, especially in scallops. In this study, the complete cholinesterase (ChE) family members have been systematically characterized in Yesso scallop (Patinopecten yessoensis) via whole-genome scanning through in silico analysis. Ten ChE family members in the genome of Yesso scallop (designated PyChEs) were identified and potentially acted to be the largest number of ChE in the reported species to date. Phylogenetic and protein structural analyses were performed to determine the identities and evolutionary relationships of these genes. The expression profiles of PyChEs were determined in all developmental stages, in healthy adult tissues, and in mantles under low pH stress (pH 6.5 and 7.5). Spatiotemporal expression suggested the ubiquitous functional roles of PyChEs in all stages of development, as well as general and tissue-specific functions in scallop tissues. Regulation expressions revealed diverse up- and down-regulated expression patterns at most time points, suggesting different functional specialization of gene superfamily members in response to ocean acidification (OA). Evidences in gene number, phylogenetic relationships and expression patterns of PyChEs revealed that functional innovations and differentiations after gene duplication may result in altered functional constraints among PyChEs gene clusters. Collectively, our results provide the potential clues that the selection pressures coming from the environment were the potential inducement leading to function allocation of ChE family members in scallop.

胆碱酯酶是中枢和外周胆碱能神经系统中的关键酶，在动物的神经冲动传递中起作用。尽管在大多数脊椎动物中已经鉴定出胆碱酯酶，但是在无脊椎动物中，尤其是在扇贝中，有关基因的可变数量和多功能的知识仍然很少。在这项研究中，完整的胆碱酯酶（ChE）家族成员已通过计算机模拟全基因组扫描在野扇贝（Patinopecten yessoensis）中进行了系统表征。在扇贝（Yesso）扇贝（指定的PyChEs）基因组中鉴定了10个ChE家族成员，并可能成为最大数量的ChE。迄今为止报道的物种中。进行了系统发育和蛋白质结构分析，以确定这些基因的身份和进化关系。在所有发育阶段，健康的成年组织中以及在低pH应力（pH 6.5和7.5）下的地幔中，测定PyChE的表达谱。时空表达表明PyChE的普遍作用在所有发育阶段，以及扇贝组织的一般功能和组织特定功能。调控表达在大多数时间点揭示了不同的上调和下调表达模式，表明响应海洋酸化（OA）的基因超家族成员的功能不同。PyChEs的基因数目，系统发育关系和表达模式的证据表明，基因复制后的功能创新和分化可能会导致PyChEs基因簇之间的功能限制发生变化。总的来说，我们的结果提供了潜在的线索，表明来自环境的选择压力是导致扇贝中ChE家族成员功能分配的潜在诱因。