Gender-enriched transcripts in Haemonchus contortus – predicted functions and genetic interactions based on comparative analyses with Caenorhabditis elegans

• Published in: International journal for parasitology 2008-01, Vol.38 (1), p.65-83
• Main Authors: Campbell, Bronwyn E., Nagaraj, Shivashankar H., Hu, Min, Zhong, Weiwei, Sternberg, Paul W., Ong, Eng K., Loukas, Alex, Ranganathan, Shoba, Beveridge, Ian, McInnes, Russell L., Hutchinson, Gareth W., Gasser, Robin B.
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; bioinformatics; Biological and medical sciences; Caenorhabditis elegans; Caenorhabditis elegans - genetics; Caenorhabditis elegans - growth & development; Caenorhabditis elegans - metabolism; Development; Differential transcription; Expressed Sequence Tags; Female; Fundamental and applied biological sciences. Psychology; gastrointestinal nematodes; Gender; gender differences; Gene Expression Profiling; gene function; gene interaction; Gene Regulatory Networks; genes; Genes, Helminth; Haemonchus - genetics; Haemonchus - growth & development; Haemonchus - metabolism; Haemonchus contortus; Helminth Proteins - metabolism; Invertebrates; Larva; Life cycle. Host-agent relationship. Pathogenesis; Male; microarray technology; Molecular Sequence Data; Nemathelminthia. Plathelmintha; Nematoda; Nematode; Oligonucleotide Array Sequence Analysis; Oligonucleotide microarray analysis; Prediction of function and genetic interactions; Protozoa; Reproduction; Reverse Transcriptase Polymerase Chain Reaction; Ruminantia; Sequence Alignment; sequence homology; transcription (genetics); Transcription, Genetic
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/j.ijpara.2007.07.001

In the present study, a bioinformatic-microarray approach was employed for the analysis of selected expressed sequence tags (ESTs) from Haemonchus contortus, a key parasitic nematode of small ruminants. Following a bioinformatic analysis of EST data using a semiautomated pipeline, 1885 representative ESTs (rESTs) were selected, to which oligonucleotides (three per EST) were designed and spotted on to a microarray. This microarray was hybridized with cyanine-dye labelled cRNA probes synthesized from RNA from female or male adults of H. contortus. Differential hybridisation was displayed for 301 of the 1885 rESTs (∼16%). Of these, 165 (55%) had significantly greater signal intensities for female cRNA and 136 (45%) for male cRNA. Of these, 113 with increased signals in female or male H. contortus had homologues in Caenorhabditis elegans, predicted to function in metabolism, information storage and processing, cellular processes and signalling, and embryonic and/or larval development. Of the rESTs with no known homologues in C. elegans, 24 (∼40%) had homologues in other nematodes, four had homologues in various other organisms and 30 (52%) had no homology to any sequence in current gene databases. A genetic interaction network was predicted for the C. elegans orthologues of the gender-enriched H. contortus genes, and a focused analysis of a subset revealed a tight network of molecules involved in amino acid, carbohydrate or lipid transport and metabolism, energy production and conversion, translation, ribosomal structure and biogenesis and, importantly, those associated with meiosis and/or mitosis in the germline during oogenesis or spermatogenesis. This study provides a foundation for the molecular, biochemical and functional exploration of selected molecules with differential transcription profiles in H. contortus, for further microarray analyses of transcription in different developmental stages of H. contortus, and for an extended functional analysis once the full genome sequence of this nematode is known.