Differential gene expression of Caenorhabditis elegans grown on unmethylated sterols or 4α-methylsterols

• Main Authors: Merris Mark, Wang Tongsheng, Soteropoulos Patricia, Lenard John
• Format: Article
• Language: English
• Published: Elsevier 2007-05-01
• Series: Journal of Lipid Research
• Subjects: transcription; reverse transcription polymerase chain reaction; microarray; cholesterol; lathosterol; lophenol
• Online Access: http://www.sciencedirect.com/science/article/pii/S002222752043562X

Transcriptional profiles of Caenorhabditis elegans grown on unmethylated sterols (desMSs) or on 4α-methylsterols (4MSs) were compared using microarrays. Thirty-four genes were upregulated and 2 were downregulated >2-fold by growth on 4MSs, including 13 cuticle collagen (col) genes, 1 cuticulin gene (cut-1), 2 groundhog-like (grl) genes, and 1 groundhog gene (grd-4); col-36 and grl-20 were increased 12- and 19-fold, respectively. Fifteen of these 17 genes have been assigned to metabolic mountain 17, suggesting coordinate 4MS-mediated regulation of expression. Quantitative RT-PCR was performed on 27–51 h old animals grown on cholesterol (a desMS) or lophenol (a 4MS). col-36 and grl-20 showed similar cyclic peaks of expression in cholesterol and similar alterations in lophenol, suggesting coregulation. Of six additional grl genes, only grl-3 was upregulated on lophenol; the rest were downregulated. Cyclicity of expression was lost or altered in all six. Nuclear receptor genes nhr-23, nhr-25, nhr-41, and daf-12 all showed cyclic expression in cholesterol and significant downregulation in lophenol by RT-PCR. Expression of the insulin-like receptor daf-2 was lower in lophenol, whereas that of its major downstream target daf-16 was higher. Thus, major changes in gene expression accompany growth on 4MSs, but with surprisingly little effect on normal growth and development.