Abstract

The oriental river prawn, Macrobrachium nipponense (De Haan, 1849), an economically important species, can live in freshwater and brackish water environments, but molecular mechanism of adaptation to varying salinity levels is still poorly understood. We aimed to investigate the effects of four different salinities (0, 6, 12, and 18‰) on metabolic responses, histological structure, and expression patterns of acid phosphatase (ACP) and alkaline phosphatase (AKP) in the hepatopancreas. The full-length cDNAs of ACP and AKP of M. nipponense (designated MnACP and MnAKP, respectively) were obtained by rapid-amplification of cDNA ends (RACE)-PCR. Immunofluorescence experiments confirmed that MnAKP is located in the cell membrane of the hepatopancreas. Both genes were expressed in all seven studied tissues, with highest expression in the hepatopancreas by quantitative real-time PCR. The mRNA expression levels and enzyme activities of MnACP and MnAKP in the hepatopancreas significantly increased in 18‰ salinity group compared to other groups. Measurements of glycogen, triglycerides, and total cholesterol levels suggested that prawns can adjust the energy metabolism in a way to provide additional energy under unsuitable salinity. Besides, prawns at high salinity produced higher B-cells and lower number of R-cells in hepatopancreatic tubules, also suggesting enhance the metabolic function of the hepatopancreas under high salinity. Our results provide a better understanding for the mechanism regulating salinity acclimation in the oriental river prawn.

中文翻译：

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盐分适应改变了东方河虾Macrobrachium nipponense（De Haan，1849）（十足目：Caridea：Palaemonidae）的肝胰腺中酸和碱性磷酸酶的表达以及组织学变化。

摘要

东方河虾，Macrobrachium nipponense（De Haan，1849年），一种经济上重要的物种，可以生活在淡水和微咸的水环境中，但对盐度变化的分子机制的了解仍然很少。我们旨在研究四种盐度（0、6、12和18‰）对肝胰腺中代谢反应，组织学结构以及酸性磷酸酶（ACP）和碱性磷酸酶（AKP）表达模式的影响。ACP的全长cDNA和AKP的日本沼虾通过分别快速扩增cDNA末端（RACE）-PCR获得（分别命名为MnACP和MnAKP）。免疫荧光实验证实MnAKP位于肝胰腺的细胞膜中。两种基因均在所有研究的七个组织中表达，通过定量实时PCR在肝胰腺中的表达最高。与其他组相比，盐度为18‰的肝胰腺中胰腺中MnACP和MnAKP的mRNA表达水平和酶活性显着增加。对糖原，甘油三酸酯和总胆固醇水平的测量表明，对虾可以调节能量代谢，从而在盐度不合适的情况下提供额外的能量。此外，高盐度虾在肝胰管中产生更高的B细胞和更低的R细胞数量，也暗示在高盐度下增强肝胰腺的代谢功能。我们的结果为调节东方河虾盐分驯化的机制提供了更好的理解。