Summary diagram indicating contraction and expansion of the chitinase/chitolectin protein family during eukaryotic evolution. A schematic of eukaryote phylogeny is shown alongside a bar graph indicating the number of chitinase/chitolectin genes identified in the genomes of selected species corresponding to the tree classifications. The schematic is according to the recent animal phylogeny suggested by multigene analyses of bilaterian animals . The species for which the number of genes is shown are the gnathostomes (jawed-vertebrates) human (Hsa), opossum (Mdo), chicken (Gga) and Xenopus (Xtr); the chordate C. intestinalis (Cin); the echinoderm S. purpuratus (Spu); the nematode C. elegans (Cel); the arthropod D. melanogaster (Dme); and the Dictyosteliida D. discoideum (Ddi), all discussed in the text. Also included in the graph are data for the fungi Aspergillis fumigatus and Saccharomyces cerevisiae and the plant Arabidopis thaliana (Additional file 7: Other chitinase sequences). The A. fumigatus and S. cerevisiae genes were obtained by querying Fungal Genomes Central at NCBI.
Funkhouser and Aronson BMC Evolutionary Biology 2007 7:96 doi:10.1186/1471-2148-7-96