Combining suppressive subtractive hybridization and cDNA microarrays to identify dietary phosphorus-responsive genes of the rainbow trout (Oncorhynchus mykiss) kidney.
Phosphorus (P)-responsive genes and how they regulate renal adaptation to phosphorous-deficient diets in animals, including fish, are not well understood. RNA abundance profiling using cDNA microarrays is an efficient approach to study nutrient-gene interactions and identify these dietary P-responsive genes. To test the hypothesis that dietary P-responsive genes are differentially expressed in fish fed varying P levels, rainbow trout were fed a practical high-P diet (R20: 0.96% P) or a low-P diet (R0: 0.38% P) for 7 weeks. The differentially-expressed genes between dietary groups were identified and compared from the kidney by combining suppressive subtractive hybridization (SSH) with cDNA microarray analysis. A number of genes were confirmed by real-time PCR, and correlated with plasma and bone P concentrations. Approximately 54 genes were identified as potential dietary P-responsive after 7 weeks on a diet deficient in P according to cDNA microarray analysis. Of 18 selected genes, 13 genes were confirmed to be P-responsive at 7 weeks by real-time PCR analysis, including: iNOS, cytochrome b, cytochrome c oxidase subunit II , alpha-globin I, beta-globin, ATP synthase, hyperosmotic protein 21, COL1A3, Nkef, NDPK, glucose phosphate isomerase 1, Na+/H+ exchange protein and GDP dissociation inhibitor 2. Many of these dietary P-responsive genes responded in a moderate way (R0/R20 ratio: <2-3 or >0.5) and in a transient manner to dietary P limitation. In summary, renal adaptation to dietary P deficiency in trout involves changes in the expression of several genes, suggesting a profile of metabolic stress, since many of these differentially-expressed candidates are associated with the cellular adaptative responses.
Lake
Jennifer
J
Pavillion Paul Comtois, Département des sciences animales, Université Laval, Québec, QC., Canada G1V 0A6.
Gravel
Catherine
C
Koko
Gabriel Koffi D
GK
Robert
Claude
C
Vandenberg
Grant W
GW
D000818:Animals; D005786:Gene Expression Regulation / Q000187:drug effects*; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism*; D009693:Nucleic Acid Hybridization / Q000379:methods*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D017686:Oncorhynchus mykiss / Q000235:genetics*; D010758:Phosphorus / Q000097:blood; D016226:Phosphorus, Dietary / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D016226:Phosphorus, Dietary; D012333:RNA, Messenger; D010758:Phosphorus