Combined RNA-Seq with small RNA revealed ribosome biogenesis and oxidative stress associated with cadmium response in carp (Cyprinus carpio L.) Hepato-pancreas

Cadmium (Cd) is one of the serious metal pollutants especially for freshwater. The carp fish can live and survive in extremely toxic conditions, providing us a useful model for studying Cd response and regulation. MicroRNAs (miRNAs) play crucial roles in regulating the expression of heavy metal exposure. However, genome-wide expression of mRNA and miRNAs in the hepato-pancreas to respond to Cd stress in carp is still unknown. In this study, we performed transcriptome sequencing to analyze Cd responding genes and enrichment pathways. We identified 21,000 expressed genes and 1726 of them with expression levels significantly changed. Most of them were involved in ribosome biogenesis. Comprehensive analysis of miRNA expression profiles in control and Cd treated carp identified 15 known differentially expressed miRNAs. Some of them have been well studied, which are mainly involved in cell growth and oxidative activities. Overall, our study identified lots of differently expressed genes (DEGs), whose functions need further studying and subset known miRNAs, which may play critical roles in Cd response.