Summary: | <p>Abstract</p> <p>Background</p> <p>Hookworms, infecting over one billion people, are the mostly closely related major human parasites to the model nematode <it>Caenorhabditis elegans</it>. Applying genomics techniques to these species, we analyzed 3,840 and 3,149 genes from <it>Ancylostoma caninum </it>and <it>A. ceylanicum</it>.</p> <p>Results</p> <p>Transcripts originated from libraries representing infective L3 larva, stimulated L3, arrested L3, and adults. Most genes are represented in single stages including abundant transcripts like hsp-20 in infective L3 and <it>vit-3 </it>in adults. Over 80% of the genes have homologs in <it>C. elegans</it>, and nearly 30% of these were with observable RNA interference phenotypes. Homologies were identified to nematode-specific and clade V specific gene families. To study the evolution of hookworm genes, 574 <it>A. caninum </it>/ <it>A. ceylanicum </it>orthologs were identified, all of which were found to be under purifying selection with distribution ratios of nonsynonymous to synonymous amino acid substitutions similar to that reported for <it>C. elegans </it>/ <it>C. briggsae </it>orthologs. The phylogenetic distance between <it>A. caninum </it>and <it>A. ceylanicum </it>is almost identical to that for <it>C. elegans </it>/ <it>C. briggsae</it>.</p> <p>Conclusion</p> <p>The genes discovered should substantially accelerate research toward better understanding of the parasites' basic biology as well as new therapies including vaccines and novel anthelmintics.</p>
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