Genes expression and in silico studies of functions of trehalases, a highly dispersed Anisakis simplex s. l. specific gene family.

Trehalase plays an important role in catabolism of trehalose, disaccharide which is one of the most widespread carbohydrates in nematode tissues. This enzyme might be a major adaptation of the nematode to parasitic lifestyle. The current study revealed five trehalase isotypes of A. simplex not yet detected in any parasitic nematode. Anisakiasis is a relatively new and rapidly spreading zoonosis that possesses a serious threat for humans and animals. The lack of methods for combating this parasite causes continuous search for new targets important in their metabolism. Here, we consider trehalase as such target gene. Trehalase genes (tre) of A. simplex shared high level of identity with free-living nematode C. elegans (76%) and parasitic nematode B. malayi (81%). The deduced amino acid sequence revealed the presence of a signal peptide at the N-terminus of the TRE protein, which is characteristic for proteins that transit through the secretory pathway. Phylogenetic analysis of the tre with homologous domains of other nematode species suggested that tre of animal- and plant-parasitic genera may have evolved in order to play an active role in the parasitism. The tre genes showed life stage-specific expression.