title: Tornado extraction: a method to enrich and purify RNA from the nephrogenic zone of the neonatal rat kidney.
abstract: BACKGROUND
  Development of the kidney is a complicated and tightly regulated process. Although several genes responsible for the renal development have been identified to date, the precise mechanisms of spatial and temporal regulation remain to be elucidated. Therefore, expanding our knowledge of molecules that are associated with nephrogenesis will be helpful to understand the whole process.
  
  
  METHODS
  To extract RNA selectively from the nephrogenic zone of the developing kidney, we developed a simple and reliable method.
  
  
  RESULTS
  This method, named "tornado extraction," enriched RNA of the nephrogenic zone by about 30-fold. In combination with the suppression subtractive hybridization, a considerable number of genes that were differentially expressed in the nephrogenic zone were obtained. These genes included a series of endodermal markers such as albumin and alpha-fetoprotein as well as GDNF (glia-derived neurotrophic factor), osteoblast-specific factor-2 (OSF-2)/periostin and fetuin (one of the major serum proteins in the fetus).
  
  
  CONCLUSIONS
  Tornado extraction has great value in studying genes in the nephrogenic zone of the developing kidney. Since the quality of RNA obtained by this method is excellent, tornado extraction is suitable in combination with other techniques including the subtractive hybridization method and DNA microarray analysis.
authors.affiliation: Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Box A8, Suita, Osaka 565-0871, Japan. taka@medone.med.osaka-u.ac.jp
authors.forename: Takahito
authors.initials: T
authors.lastname: Ito
authors.forename: Akira
authors.initials: A
authors.lastname: Suzuki
authors.forename: Enyu
authors.initials: E
authors.lastname: Imai
authors.forename: Naoko
authors.initials: N
authors.lastname: Horimoto
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Daikuhara
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Hori
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015415:Biomarkers; D015152:Blotting, Northern; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D007668:Kidney / Q000254:growth & development* / Q000502:physiology*; D012313:RNA / Q000302:isolation & purification*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D015415:Biomarkers; D012313:RNA