University of Maryland Center for Environmental Science, Institute of Marine and Environmental Technology, Columbus Center, Baltimore, MD, USA.
Gen Comp Endocrinol. 2011 Aug 1;173(1):4-10. doi: 10.1016/j.ygcen.2011.04.017. Epub 2011 May 10.
In malacostracan crustaceans, sex differentiation is uniquely regulated by a hormone secreted by the male-specific androgenic gland (AG). An isopod AG hormone was the first to be structurally elucidated and was found to belong to the insulin superfamily of proteins. Recently, it has been found that the AGs of several decapod crustaceans express insulin-like androgenic gland factors (IAGs), whose function is believed to be similar to that of the isopod AG hormone. Here we report the isolation from the blue crab Callinectes sapidus of the full-length cDNA encoding a candidate insulin-like AG hormone, termed Cas-IAG. The predicted protein Cas-IAG was encoded as a precursor consisting of a signal peptide, the B chain, the C peptide, and the A chain in that order. While the AG was the main source of Cas-IAG expression, as found in other decapod species, the hepatopancreas of male Callinectes sapidus crabs displayed minor Cas-IAG expression. Eyestalk ablation confirmed the presence of a possible endocrine axis between the eyestalk ganglia and the AG, implying that Cas-IAG expression is negatively regulated by (a) substance(s) present in the eyestalk ganglia.
在软甲亚纲甲壳动物中，性别分化是由雄性特异性的雄激素腺（AG）分泌的激素独特地调节的。一种等足动物的 AG 激素是第一个被结构阐明的，并被发现属于胰岛素超家族的蛋白质。最近，发现几种十足目甲壳动物的 AG 表达胰岛素样雄激素腺因子（IAGs），其功能被认为与等足动物的 AG 激素相似。在这里，我们从蓝蟹 Callinectes sapidus 中分离出编码候选胰岛素样 AG 激素的全长 cDNA，称为 Cas-IAG。预测的 Cas-IAG 蛋白被编码为一个前体，由信号肽、B 链、C 肽和 A 链依次组成。虽然 AG 是 Cas-IAG 表达的主要来源，就像在其他十足目物种中一样，但雄性 Callinectes sapidus 蟹的肝胰腺显示出 Cas-IAG 的少量表达。眼柄切除证实了眼柄神经节和 AG 之间存在可能的内分泌轴，这表明 Cas-IAG 的表达受到（a）眼柄神经节中存在的物质的负调控。
