Differential gene expression analysis implicates wild Magallana bilineata (Röding, 1798) to be in an enhanced immunological status than laboratory-maintained oysters

Oysters are filter-feeding bivalves thriving in estuaries and inter-tidal zones. As sessile invertebrates, oysters have evolved a well-developed stress tolerance mechanism to tolerate various environmental stressors such as altered hydrological parameters, microbial pathogens, and anthropogenic influences. The focus of this study was to identify the key genes which enable the Indian oyster (Magallana bilineata) to overcome the turbulent conditions in their environment. Suppression subtractive hybridization (SSH) technique was used to generate the differentially expressed genes in wild Magallana bilineata in comparison to laboratory-maintained ones. The method revealed twenty functionally relevant genes with roles in immunity, stress, cellular processes, cytoskeleton, and lipid metabolism. The diverse set of genes obtained from the SSH library are known to have direct and indirect roles in oyster immunity, suggesting that the wild oysters are more immune stimulated and active than laboratory-maintained ones. The expression of ten potentially upregulated genes was analysed using quantitative real-time PCR.