A novel chitinase from the earthworm, Eisenia andrei

A novel chitinase gene, EaChi, and its expression pattern from the earthworm, E. andrei are demonstrated. Based on a deduced amino acid sequence, in EaChi, two specific domains for GH family 18 are well conserved with two essential amino acid residues for enzyme activity. The phylogenetic analysis shows that earthworm chitinase, EaChi, is evolutionarily close to other lophotrochozoan chitinases. The expression pattern analysis of EaChi indicates that the major expression is localized at intestinal epithelium and epidermis, possibly suggesting that the prime functions of the chitinase activity could be related to not only digestive process but also self-defending immunity as a biochemical barrier to protect the invasion of chitin-containing pathogens, including fungi, nematodes and protozoa.