Key Lab of the Ministry of Education for Coastal and Wetland Ecosystems, School of Life Sciences, Xiamen University, Xiamen 361005, China.
Fish Shellfish Immunol. 2010 Jul;29(1):75-81. doi: 10.1016/j.fsi.2010.02.014. Epub 2010 Mar 1.
GH18 chitinase is a multi-gene family. The family plays important physiological roles in Crustacea, e.g. ecdysis and defense against pathogen. However, data about GH18 family are rather limited in Crustacea. In the study, different cloning strategies were adopted to clone chitinase genes of Litopenaeus vannamei, which is the most widely cultured shrimp. Seven chitinase family members were identified. Analysis of domain architectures showed the repeated CBM18 modules and catalytic domain of enzymatically inactive chitolectin in Crustacea for the first time. Comparing to the three known groups of crustacean chitinase, four of the seven members are located on new evolutionary clades thus enriched the chitinase family of Crustacea. Tissue expression profiles were investigated in eight tissues. Expression of CHT5 and CHID1 were both detected in the hemocyte by which the innate immunity activity was carried out. The domain architectures, evolutionary relationships and tissue expression patterns all provide reasonable explanation for the existence of multiple genes in crustacean chitinase family.
GH18 几丁质酶是一个多基因家族。该家族在甲壳动物中发挥着重要的生理作用，例如蜕皮和抵御病原体。然而，甲壳动物中 GH18 家族的数据相当有限。在这项研究中，采用了不同的克隆策略来克隆凡纳滨对虾的几丁质酶基因，凡纳滨对虾是养殖最广泛的虾类。鉴定出了 7 个几丁质酶家族成员。结构域架构分析首次显示了甲壳动物中重复的 CBM18 模块和无活性的几丁质凝集素的催化结构域。与已知的三种甲壳动物几丁质酶相比，这 7 个成员中的 4 个位于新的进化枝上，从而丰富了甲壳动物的几丁质酶家族。在 8 种组织中进行了组织表达谱研究。通过进行先天免疫的血细胞检测到了 CHT5 和 CHID1 的表达。结构域架构、进化关系和组织表达模式都为甲壳动物几丁质酶家族中多个基因的存在提供了合理的解释。
