Abstract
Oysters are a globally distributed aquatic economic shellfish with a remarkable ability to accumulate cadmium (Cd). The phenomenon of Cd content exceeding safety standards in oysters occurs frequently, posing a significant risk to food safety. In this study, Portuguese oysters (Crassostrea angulata) were exposed to 2 μg/L of Cd for 15 days. Individuals with significantly different Cd accumulation were selected for transcriptomic sequencing analysis. KEGG enrichment analysis revealed that the differentially expressed genes (DEGs) between high- and low-Cd-accumulation individuals, as well as those before and after Cd exposure, were primarily enriched in metabolic pathways (33.8%) and organismal systems (32.2%). ABC transporters, phagosomes, glutathione metabolism, and the biosynthesis of amino acids played crucial roles in Cd accumulation and detoxification processes. Metal cation transport-related genes, including zip1, copt5.1, and orct2, may be involved in the Cd transport process in Portuguese oysters, and their differential expression influences Cd accumulation in the soft tissues. Meanwhile, genes such as sod3, cyp4f22, and abca3 are likely to play significant roles in detoxification under Cd exposure. Additionally, alternative splicing analysis identified 13 potential genes associated with Cd response in Portuguese oysters, including cs2, gfpt1, and acox1.