Research

Divergent evolution of arrested development in the dauer stage of Caenorhabditis elegans and the infective stage of Heterodera glycines

Axel A Elling^1,2,3 , Makedonka Mitreva⁴ , Justin Recknor⁵ , Xiaowu Gai^6,7 , John Martin⁴ , Thomas R Maier² , Jeffrey P McDermott^2,8 , Tarek Hewezi² , David McK Bird⁹ , Eric L Davis⁹ , Richard S Hussey¹⁰ , Dan Nettleton⁵ , James P McCarter^4,11 and Thomas J Baum^1,2

¹  Interdepartmental Genetics Program, Iowa State University, Ames, IA 50011, USA

²  Department of Plant Pathology, Iowa State University, Ames, IA 50011, USA

³  Current address: Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA

⁴  Department of Genetics, Washington University School of Medicine, Genome Sequencing Center, St Louis, MO 63108, USA

⁵  Department of Statistics, Iowa State University, Ames, IA 50011, USA

⁶  LH Baker Center for Bioinformatics and Biological Statistics, Iowa State University, Ames, IA 50011, USA

⁷  Current address: Center for Biomedical Informatics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA

⁸  Current address: The University of Kansas Medical Center, Kansas City, KS 66160, USA

⁹  Department of Plant Pathology, NC State University, Raleigh, NC 27695, USA

¹⁰  Department of Plant Pathology, University of Georgia, Athens, GA 30602, USA

¹¹  Divergence Inc., North Warson Road, St Louis, MO 63141, USA

author email corresponding author email

Genome Biology 2007, 8:R211doi:10.1186/gb-2007-8-10-r211

Published:	5 October 2007

Subject areas: Development, Genome studies, Model organisms

Abstract

Background

The soybean cyst nematode Heterodera glycines is the most important parasite in soybean production worldwide. A comprehensive analysis of large-scale gene expression changes throughout the development of plant-parasitic nematodes has been lacking to date.

Results

We report an extensive genomic analysis of H. glycines, beginning with the generation of 20,100 expressed sequence tags (ESTs). In-depth analysis of these ESTs plus approximately 1,900 previously published sequences predicted 6,860 unique H. glycines genes and allowed a classification by function using InterProScan. Expression profiling of all 6,860 genes throughout the H. glycines life cycle was undertaken using the Affymetrix Soybean Genome Array GeneChip. Our data sets and results represent a comprehensive resource for molecular studies of H. glycines. Demonstrating the power of this resource, we were able to address whether arrested development in the Caenorhabditis elegans dauer larva and the H. glycines infective second-stage juvenile (J2) exhibits shared gene expression profiles. We determined that the gene expression profiles associated with the C. elegans dauer pathway are not uniformly conserved in H. glycines and that the expression profiles of genes for metabolic enzymes of C. elegans dauer larvae and H. glycines infective J2 are dissimilar.

Conclusion

Our results indicate that hallmark gene expression patterns and metabolism features are not shared in the developmentally arrested life stages of C. elegans and H. glycines, suggesting that developmental arrest in these two nematode species has undergone more divergent evolution than previously thought and pointing to the need for detailed genomic analyses of individual parasite species.