Dopamine beta-hydroxylase (DβH) plays an essential role in the synthesis of catecholamines (CA) in neuroendocrine networks. In the razor clam, Sinonovacula constricta a novel gene for DβH (ScDβH-α) was identified that belongs to the copper type II ascorbate-dependent monooxygenase family. Expression analysis revealed ScDβH-α gene transcripts were abundant in the liver and expressed throughout development. Knock-down of ScDβH-α in adult clams using siRNA caused a reduction in the growth rate compared to control clams. Reduced growth was associated with strong down-regulation of gene transcripts for the growth-related factors, platelet derived growth factors A (PDGF-A) (P < 0.001) 24 h after ScDβH-α knock-down, vascular endothelial growth factor (VEGF1) (P < 0.001) and platelet derived growth factor B (PDGF-B-2) (P < 0.001) 24 h and 48 h after ScDβH-α knock-down and transforming growth factor beta (TGF-β1) (P < 0.001) 48 h and 72 h after ScDβH-α knock-down. Taken together the results suggest that the novel ScDβH-α gene through its role in CA synthesis is involved in growth regulation in the razor clam and possibly other bivalves.

多巴胺β-羟化酶（DβH）在神经内分泌网络中儿茶酚胺（CA）的合成中起重要作用。在剃须刀蛤中，发现了Sinonovacula constricta一个新的DβH基因（ScDβH-α），该基因属于II型铜抗坏血酸依赖性单加氧酶家族。表达分析表明，ScDβH-α基因转录本在肝脏中丰富，并在整个发育过程中表达。与对照蛤相比，使用siRNA敲除成年蛤中ScDβH-α导致生长速率降低。生长降低与生长相关因子，血小板衍生生长因子A（PDGF-A）的基因转录产物强烈下调有关（ScDβH-α敲除后24 h，P <0.001），血管内皮生长因子（VEGF1）（P <0.001）和血小板衍生生长因子B（PDGF-B-2）（P <0.001），分别在24 h和48 h后出现ScDβH-α敲除后48 h和72 h，ScDβH-α敲除和转化生长因子β（TGF-β1）（P <0.001）。综上所述，结果表明新的ScDβH-α基因通过其在CA合成中的作用参与了剃刀蛤和其他双壳类的生长调节。