Poulos J E, Gower W R, Friedl F E, Vesely D L
Department of Biology, University of South Florida, Tampa 33612, USA.
Gen Comp Endocrinol. 1995 Oct;100(1):61-8. doi: 10.1006/gcen.1995.1133.
The present investigation was designed to (1) determine if atrial natriuretic factor gene expression occurs within invertebrates as well as within vertebrates; (2) determine whether the product of this gene expression is the 126-amino-acid atrial natriuretic factor prohormone or some other molecular species; and (3) evaluate within the same invertebrates if the products of atrial natriuretic factor gene expression are released into their circulation. Utilizing a very sensitive RNase protection assay it was found that atrial natriuretic peptide gene expression occurs within the heart of the oyster, Crassostrea virginica, and within the heart of the blue crab, Callinectes sapidus, but was expressed sevenfold less than in a vertebrate heart (i.e., rat, Rattus norvegiucs). High-performance gel-permeation chromatography followed by N-terminal and C-terminal atrial natriuretic factor prohormone radioimmunoassays indicated that the molecular species synthesized within the oyster and blue crab hearts was the atrial natriuretic factor prohormone. The product(s) of this atrial natriuretic factor gene expression (i.e., atrial natriuretic peptides) was found to be released into the circulation, i.e., hemolymph, of both the oyster and the blue crab.
(1) 确定心房利钠因子基因表达是否在无脊椎动物以及脊椎动物体内发生；(2) 确定该基因表达的产物是126个氨基酸的心房利钠因子原激素还是其他某种分子形式；(3) 在同一无脊椎动物体内评估心房利钠因子基因表达的产物是否释放到其循环系统中。利用一种非常灵敏的核糖核酸酶保护分析方法，发现心房利钠肽基因表达发生在弗吉尼亚牡蛎（Crassostrea virginica）的心脏以及青蟹（Callinectes sapidus）的心脏中，但表达量比脊椎动物心脏（即大鼠，Rattus norvegiucs）少7倍。采用高效凝胶渗透色谱法，随后进行N端和C端心房利钠因子原激素放射免疫分析，结果表明在牡蛎和青蟹心脏中合成的分子形式是心房利钠因子原激素。发现这种心房利钠因子基因表达的产物（即心房利钠肽）释放到了牡蛎和青蟹的循环系统中，即血淋巴中。
