Bao X B, He C B, Fu C D, Wang B, Zhao X M, Gao X G, Liu W D
Liaoning Key Laboratory of Marine Fishery Molecular Biology, Liaoning Ocean and Fisheries Science Research Institute, Dalian, China.
School of Food Science and Technology, Dalian Polytechnic University, Dalian, China.
Genet Mol Res. 2015 Mar 27;14(1):2253-67. doi: 10.4238/2015.March.27.11.
C-type lectins are a superfamily of Ca(2+)-dependent carbohydrate-recognition proteins that are well known for their participation in pathogen recognition and clearance. In this study, a putative C-type lectin fold (MyCLF) gene was identified from the Japanese scallop Mizuhopecten yessoensis. The full-length of MyCLF was 645 bp, encoding a polypeptide of 167 amino acids. MyCLF carried a signal peptide of 20 amino acid residues, and a single carbohydrate recognition domain, having relatively high amino acid sequence conservation with C-type lectins reported for other bivalves. The expression of MyCLF mRNA transcripts in adult tissues, after bacterial challenge and during different developmental stages was determined using real-time quantitative RT-PCR. MyCLF was mainly distributed in the mantle, gill, and kidney. The expression of MyCLF clearly increased 3 h after Vibrio anguillarum challenge, and dropped to a minimum level after 9 h compared to the control group. During embryonic development, the expression level increased in the gastrulae, trochophore and early D-shaped larvae, decreased in D-shaped larvae, and then increased hundreds of times in metamorphosing larvae. The results suggested that MyCLF was involved in an immune response and it may play important roles during the metamorphosis phase of M. yessoensis.
C型凝集素是一类依赖钙离子的碳水化合物识别蛋白超家族，因其参与病原体识别和清除而闻名。在本研究中，从日本扇贝（虾夷扇贝）中鉴定出一个假定的C型凝集素折叠（MyCLF）基因。MyCLF全长645 bp，编码一个由167个氨基酸组成的多肽。MyCLF带有一个由20个氨基酸残基组成的信号肽和一个单一的碳水化合物识别结构域，与其他双壳贝类报道的C型凝集素具有较高的氨基酸序列保守性。使用实时定量RT-PCR测定MyCLF mRNA转录本在成体组织、细菌攻击后以及不同发育阶段的表达情况。MyCLF主要分布在套膜、鳃和肾脏中。鳗弧菌攻击后3小时，MyCLF的表达明显增加，与对照组相比，9小时后降至最低水平。在胚胎发育过程中，原肠胚、担轮幼虫和早期D形幼虫阶段表达水平升高，D形幼虫阶段表达水平下降，然后在变态幼虫阶段增加数百倍。结果表明，MyCLF参与免疫反应，并且可能在虾夷扇贝的变态阶段发挥重要作用。
