Differential gene expression of Caenorhabditis elegans grown on unmethylated sterols or 4alpha-methylsterols.
Transcriptional profiles of Caenorhabditis elegans grown on unmethylated sterols (desMSs) or on 4alpha-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.
Merris
Mark
M
Department of Physiology and Biophysics, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
Wang
Tongsheng
T
Soteropoulos
Patricia
P
Lenard
John
J
D000818:Animals; D017173:Caenorhabditis elegans / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics*; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics*; D008745:Methylation; D015394:Molecular Structure; D020411:Oligonucleotide Array Sequence Analysis; D013261:Sterols / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics*
D029742:Caenorhabditis elegans Proteins; D013261:Sterols