Research article

A decline in transcript abundance for Heterodera glycines homologs of Caenorhabditis elegans uncoordinated genes accompanies its sedentary parasitic phase

Vincent P Klink^1* , Veronica E Martins^1,2* , Nadim W Alkharouf³ , Christopher C Overall⁴ , Margaret H MacDonald¹ and Benjamin F Matthews^1,4

¹  United States Department of Agriculture, Soybean Genomics and Improvement Laboratory, Beltsville, MD 20705, USA

²  Graduate School of Biotechnology Studies, University of Maryland University College, Adelphi, MD 20783, USA

³  Jess and Mildred Fisher College of Science and Mathematics, Department of Computer and Information Sciences, Towson University, 7800 York Road, Towson, Maryland 21252, USA

⁴  Department of Bioinformatics and Computational Biology, George Mason University, Manassas 20110, VA, USA

author email corresponding author email* Contributed equally

BMC Developmental Biology 2007, 7:35doi:10.1186/1471-213X-7-35

Published:	19 April 2007

Abstract

Background

Heterodera glycines (soybean cyst nematode [SCN]), the major pathogen of Glycine max (soybean), undergoes muscle degradation (sarcopenia) as it becomes sedentary inside the root. Many genes encoding muscular and neuromuscular components belong to the uncoordinated (unc) family of genes originally identified in Caenorhabditis elegans. Previously, we reported a substantial decrease in transcript abundance for Hg-unc-87, the H. glycines homolog of unc-87 (calponin) during the adult sedentary phase of SCN. These observations implied that changes in the expression of specific muscle genes occurred during sarcopenia.

Results

We developed a bioinformatics database that compares expressed sequence tag (est) and genomic data of C. elegans and H. glycines (CeHg database). We identify H. glycines homologs of C. elegans unc genes whose protein products are involved in muscle composition and regulation. RT-PCR reveals the transcript abundance of H. glycines unc homologs at mobile and sedentary stages of its lifecycle. A prominent reduction in transcript abundance occurs in samples from sedentary nematodes for homologs of actin, unc-60B (cofilin), unc-89, unc-15 (paromyosin), unc-27 (troponin I), unc-54 (myosin), and the potassium channel unc-110 (twk-18). Less reduction is observed for the focal adhesion complex gene Hg-unc-97.

Conclusion

The CeHg bioinformatics database is shown to be useful in identifying homologs of genes whose protein products perform roles in specific aspects of H. glycines muscle biology. Our bioinformatics comparison of C. elegans and H. glycines genomic data and our Hg-unc-87 expression experiments demonstrate that the transcript abundance of specific H. glycines homologs of muscle gene decreases as the nematode becomes sedentary inside the root during its parasitic feeding stages.