Table 2 Number of differentially expressed genes (DEGs) obtained by comparing clams exposed to sediments collected in Vittorio Emanuele III channel (sites I, II, II, IV and V; 10 biological replicates for each exposure) with clams exposed to sediments collected in control site (site VI; 10 biological replicates). For each comparison, the total number of upregulated (↑) and downregulated genes (↓) in samples of each treatment are also reported