Figure 5. Proposed role of cgi-miR-2d in oyster immune response by targeting CgIκB2.
Given the expression changes of cgi-miR-2d and CgIκB2, it was suggested that CgIκB2 could be modulated post-transcriptionally by up-regulated cgi-miR-2d at the early stage of V. splendidus infection and led to the inhibition of NF-κB pathway activation as well as the promotion of haemocyte phagocytosis. At the late stage of V. splendidus challenge, expression of cgi-miR-2d was repressed while that of CgIκB2 was up-regulated to disadvantage both NF-κB pathway and haemocyte phagocytosis. Moreover, apoptosis could also be regulated by cgi-miR-2d, which was conserved among miR-2 family yet not dominant during V. splendidus challenge, indicating the existence of other unknown modulatory pathways.