Biomphalaria glabrata is a freshwater Planorbidae snail. In its environment, 
this mollusk faces numerous microorganisms or pathogens, and has developed 
sophisticated innate immune mechanisms to survive. The mechanisms of recognition 
are quite well understood in Biomphalaria glabrata, but immune effectors have 
been seldom described. In this study, we analyzed a new family of potential 
immune effectors and characterized five new genes that were named Glabralysins. 
The five Glabralysin genes showed different genomic structures and the high 
degree of amino acid identity between the Glabralysins, and the presence of the 
conserved ETX/MTX2 domain, support the hypothesis that they are pore-forming 
toxins. In addition, tertiary structure prediction confirms that they are 
structurally related to a subset of Cry toxins from Bacillus thuringiensis, 
including Cry23, Cry45, and Cry51. Finally, we investigated their gene 
expression profiles in snail tissues and demonstrated a mosaic transcription. We 
highlight the specificity in Glabralysin expression following immune stimulation 
with bacteria, yeast or trematode parasites. Interestingly, one Glabralysin was 
found to be expressed in immune-specialized hemocytes, and two others were 
induced following parasite exposure.