Comparative accumulation and transcriptomic analysis of juvenile Marsupenaeus japonicus under cadmium or copper exposure

Abstract

Waterborne metals may be hazardous to aquatic organisms and trigger stress responses. The present study aimed to assess the effect of exposure to 100 μg/L cadmium (Cd) or copper (Cu) for 48 h on juvenile Marsupenaeus japonicus, in terms of bioaccumulation and the whole body transcriptome. The results demonstrated that Cu accumulation in M. japonicas was much higher than that of Cd. Meanwhile, transcriptome analysis identified 1802 and 2670 differentially expressed genes (DEGs) after 48 h exposure to 100 μg/L Cd and Cu, respectively. Among them, 851 DEGs responded to both metals. Cd and Cu stress shared genes were related to the cytoskeleton, immunity, antioxidation, and detoxification. Metallothionein 1 (MT1) was specifically induced in the Cd-stress response, while glycometabolism, heat shock protein 90 (HSP90), metallothionein 2 (MT2), apoptosis, and iron transport-related genes were changed specifically in response to Cu stress. In addition, real-time PCR was used to verify the expression patterns of 28 randomly selected DEGs. The sequencing and real-time PCR results were consistent. Moreover, based on the number of significantly modulated genes and their expression levels, we deduced that Cu acts as a stronger stress inducer than Cd in M. japonicus. The identified Cd and Cu stress related genes and pathways will provide new insights into the common and different molecular mechanisms underlying Cd and Cu toxicity effects in M. japonicus.