PDF(Pubmed)
Abstract：
Carotenoid cleavage oxygenases can cleave carotenoids into a range of biologically important products. Carotenoid isomerooxygenase (NinaB) and β, β-carotene 15, 15\'-monooxygenase (BCO1) are two important oxygenases. In order to understand the roles that both oxygenases exert in crustaceans, we first investigated NinaB-like (EsNinaBl) and BCO1-like (EsBCO1l) within the genome of Chinese mitten crab (Eriocheir sinensis). Their functions were then deciphered through an analysis of their expression patterns, an in vitro β-carotene degradation assay, and RNA interference. The results showed that both EsNinaBl and EsBCO1l contain an RPE65 domain and exhibit high levels of expression in the hepatopancreas. During the molting stage, EsNinaBl exhibited significant upregulation in stage C, whereas EsBCO1l showed significantly higher expression levels at stage AB. Moreover, dietary supplementation with β-carotene resulted in a notable increase in the expression of EsNinaBl and EsBCO1l in the hepatopancreas. Further functional assays showed that the EsNinaBl expressed in E. coli underwent significant changes in its color, from orange to light; in addition, its β-carotene cleavage was higher than that of EsBCO1l. After the knockdown of EsNinaBl or EsBCO1l in juvenile E. sinensis, the expression levels of both genes were significantly decreased in the hepatopancreas, accompanied by a notable increase in the redness (a*) values. Furthermore, a significant increase in the β-carotene content was observed in the hepatopancreas when EsNinaBl-mRNA was suppressed, which suggests that EsNinaBl plays an important role in carotenoid cleavage, specifically β-carotene. In conclusion, our findings suggest that EsNinaBl and EsBCO1l may exhibit functional co-expression and play a crucial role in carotenoid cleavage in crabs.
摘要：
类胡萝卜素裂解加氧酶可以将类胡萝卜素裂解成一系列生物学上重要的产物。类胡萝卜素异氧化酶（NinaB）和β，β-胡萝卜素15,15'-单加氧酶(BCO1)是两种重要的加氧酶。为了了解两种加氧酶在甲壳类动物中的作用，我们首先研究了中华绒螯蟹（Eriocheirsinensis）基因组中的NinaB样（EsNinaBl）和BCO1样（EsBCO1l）。然后通过分析它们的表达模式来破译它们的功能，体外β-胡萝卜素降解试验，和RNA干扰。结果显示,EsNinaBl和EsBCO1l都含有RPE65结构域,并且在肝胰腺中表现出高水平的表达。在蜕皮阶段，EsNinaBl在C阶段表现出显着的上调，而EsBCO1l在AB阶段显示出显著较高的表达水平。此外，饮食中补充β-胡萝卜素导致肝胰腺中EsNinaBl和EsBCO1l的表达显着增加。进一步的功能测定表明，在大肠杆菌中表达的EsNinaBl经历了其颜色的显著变化，从橙色到浅色；此外，其β-胡萝卜素裂解率高于EsBCO1l。在中华幼年大肠杆菌中击倒EsNinaBl或EsBCO1l后，这两个基因的表达水平在肝胰腺中显著降低，伴随着红色(a*)值的显着增加。此外，当EsNinaBl-mRNA被抑制时，在肝胰腺中观察到β-胡萝卜素含量的显着增加，这表明EsNinaBl在类胡萝卜素裂解中起着重要作用，特别是β-胡萝卜素。总之,我们的发现表明，EsNinaBl和EsBCO1l可能表现出功能性共表达，并在螃蟹的类胡萝卜素裂解中起关键作用。
