Molecular studies on the formation of calcified hard tissues in marine crustaceans

海洋甲壳动物钙化硬组织形成的分子研究

基本信息

批准号：
08833004
负责人：
WATANABE Toshiki
金额：
$ 1.34万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08833004/
关键词：
calcification crustacean hard tissue exoskeleton molt calcium chitin chitinase 表皮

项目摘要

This study was carried out to identify mRNAs encoding proteins which regulate formation of the exoskeleton (with particular intesest in the calcification process) in the marine crustacean Penaeus japonicus. For this purpose, mRNAs that were expressed specifically or predominantly at postmolt stages (the exoskeleton becomes calcified at these stages) in cuticular body parts were sought using the differential display and Northern analyzes.In this study, six mRNA species exhibiting the above expression profile were identified, and for four out of the six, cDNA clones isolated. Nucleotide sequences were obtained and analyzed for three mRNA species (named DD-1,4, and 9). DD-1 contained a coding sequence for an asparagine-rich alkaline protein which resembled no known proteins. The conceptual DD-9 protein exhibited sequence similarities to a family of small proteins constituting insect cuticle. DD-4 seemed to encode a proline-rich acidic protein whose sequence was similar to that of the calcium binding protein calphotin. It is of great interest to elucidate the function of the DD-4 protein in the calcification of the crustacean exoskeleton.In this study, a cDNA encoding a putative chitinase (endo-type chitinolytic enzyme) was isolated from cuticular body parts of P.japonicus. This protein was distinct form the chitinases expressed in the digestive organ hepatopancreas.

本研究的目的是鉴定编码调节海洋甲壳类日本对虾外骨骼形成（特别是钙化过程）的蛋白质的 mRNA。为此，使用差异显示和 Northern 分析寻找在蜕皮后阶段（外骨骼在这些阶段钙化）在角质体部分中特异性表达或主要表达的 mRNA。在这项研究中，展示了上述表达谱的 6 种 mRNA 是鉴定出 6 个克隆中的 4 个，并分离出 cDNA 克隆。获得并分析了三种 mRNA 种类（名为 DD-1,4 和 9）的核苷酸序列。 DD-1 含有富含天冬酰胺的碱性蛋白质的编码序列，该蛋白质与任何已知蛋白质都不相似。 DD-9 概念蛋白与构成昆虫角质层的小蛋白家族表现出序列相似性。 DD-4 似乎编码一种富含脯氨酸的酸性蛋白，其序列与钙结合蛋白钙磷蛋白的序列相似。阐明 DD-4 蛋白在甲壳动物外骨骼钙化中的功能非常有意义。在本研究中，从日本对虾的角质体部分中分离出编码假定的几丁质酶（内型几丁质分解酶）的 cDNA 。这种蛋白质与消化器官肝胰腺中表达的几丁质酶不同。