Research article

Investigating hookworm genomes by comparative analysis of two Ancylostoma species

Makedonka Mitreva^1* , James P McCarter^1,2* , Prema Arasu³ , John Hawdon⁴ , John Martin¹ , Mike Dante¹ , Todd Wylie¹ , Jian Xu¹ , Jason E Stajich⁵ , Wadim Kapulkin^6,7 , Sandra W Clifton¹ , Robert H Waterston^1,8 and Richard K Wilson¹

¹  Genome Sequencing Center, Department of Genetics, Washington University School of Medicine, St. Louis, MO 63108, USA

²  Divergence Inc., St. Louis, MO 63141, USA

³  College of Veterinary Medicine, Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27606, USA

⁴  Department of Microbiology and Tropical Medicine, George Washington University Medical Center, Washington, DC 20037, USA

⁵  Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27710, USA

⁶  Department of Infectious Diseases, Microbiology and Parasitology, Faculty of Veterinary Medicine, Warsaw Agricultural University, Warszawa, Poland

⁷  School of Biology, University of Leeds, LEEDS LS2 9JT, UK

⁸  Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA

author email corresponding author email* Contributed equally

BMC Genomics 2005, 6:58doi:10.1186/1471-2164-6-58

Published:	26 April 2005

Abstract

Background

Hookworms, infecting over one billion people, are the mostly closely related major human parasites to the model nematode Caenorhabditis elegans. Applying genomics techniques to these species, we analyzed 3,840 and 3,149 genes from Ancylostoma caninum and A. ceylanicum.

Results

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 vit-3 in adults. Over 80% of the genes have homologs in C. elegans, 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 A. caninum / A. ceylanicum 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 C. elegans / C. briggsae orthologs. The phylogenetic distance between A. caninum and A. ceylanicum is almost identical to that for C. elegans / C. briggsae.

Conclusion

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.