合浦珠母贝BMP7b基因的克隆与表达分析

Molecular cloning and expression analysis of BMP7b from Pinctada fucata

为了解骨形态发生蛋白(BMP)在贝类生物矿化方面的作用,该研究发现并克隆了合浦珠母贝(Pinctada fucata)BMP7的同源基因BMP7b,并对其进行了组织表达分析。结果显示,该基因c DNA长2 464 bp,其中ORF长1 194 bp,编码397个氨基酸。BMP7b蛋白无跨膜结构,含有1个信号肽(1~26 aa),1个TGF-β前肽结构域(25~240 aa)和1个TGF-β结构域(299~396 aa)。BMP7b在各组织和各胚胎发育时期中均有表达,在鳃和外套膜的表达量高,在肠和肝胰腺的表达量低;在担轮幼虫期的表达量远远高于其他时期。贝壳缺刻实验显示24 h后,BMP7b表达量显著上升。以上结果表明BMP7b可能在合浦珠母贝贝壳形成和修护过程中起重要作用。

In order to understand the role of BMP in biomineralization process in mollusca, a BMP7 homolog in Pinctadafucata named BMP7b was cloned in this study. The full length of BMP7b was 2 464 bp, including an open reading frame （ORF） of 1 194 bp which encoded 397 amino acids. The protein sequence included a signal peptide （1-26 aa）, a pro-domain （25-240 aa） and a TGF-J3 domain （299-396 aa）. No transmembrane domain was detected. BMPTb was expressed in all kinds of tissues and was higher ex- pressed in gill and mantle, but lower in intestine and hepatopancreas. The BMP7b expression level at larva stage was much higher than that in other periods. In shell notch experiment, BMP7b showed increasing expression level after 24 h. These results indicate that BMP7b may play an important role in process of shell formation and repairment.