Identification and characterization of pufflectin from the grass pufferfish Takifugu niphobles and comparison of its expression with that of Takifugu rubripes

• An orthologue of pufflectin (Tn pufflectin) was identified in Takifugu niphobles.
• Tn pufflectin was mainly expressed in the skin, gills, brain, and muscles.
• The deduced Tn pufflectin amino acid sequence conserved two mannose-binding domains.
• Recombinant Tn pufflectin exhibited binding activity to d-mannose.
• Pufflectin expression is higher in a species susceptible to a monogenean parasite.

Pufflectin found in Takifugu rubripes (Tr pufflectin) is the first animal lectin reported to show sequence similarity to monocotyledonous plant lectins. In the present study, we identified and characterized an orthologous lectin from Takifugu niphobles (Tn pufflectin), a species closely related to T. rubripes. Tn pufflectin exhibits 86% identity to Tr pufflectin with two conserved mannose-binding domains. Tn pufflectin was mainly expressed in the skin, gills, brain, and muscles; however, it was expressed at a lower level in the other examined tissues. Recombinant Tn pufflectin, expressed by Escherichia coli, exhibited binding activity specific for d-mannose. The expression of pufflectin in the gills was much lower in T. niphobles than in T. rubripes; notably, the former and latter are resistant and susceptible, respectively, to the monogenean parasite Heterobothrium okamotoi, which parasitizes gills. This suggests that pufflectin might be utilized by the parasite for host recognition.