title: Sequence analysis of coding and 3' and 5' flanking regions of the epithelial sodium channel alpha, beta, and gamma genes in Dahl S versus R rats.
abstract: BACKGROUND
  To test whether epithelial sodium channel (ENaC) genes' variants contribute to salt sensitive hypertension in Dahl rats, we screened ENaC alpha, beta, and gamma genes entire coding regions, intron-exon junctions, and the 3' and 5' flanking regions in Dahl S, R and Wistar rats using both Denaturing High Performance Liquid Chromatography (DHPLC) and sequencing.
  
  
  RESULTS
  Our analysis revealed no sequence variability in the three genes encoding ENaC in Dahl S versus R rats. One homozygous sequence variation predicted to result in a D75E substitution was identified in Dahl and Wistar rat ENaC alpha compared to Brown Norway. Six and two previously reported polymorphic sites in Brown Norway sequences were lost in Dahl and Wistar rats, respectively. In the 5' flanking regions, we found a deletion of 5GCTs in Dahl and Wistar rat ENaC alpha gene, five new polymorphic sites in ENaC beta and gamma genes, one homozygous sequence variation in Dahl and Wistar rat ENaC gamma gene, as well as one Dahl rat specific homozygous insertion of -1118CCCCCA in ENaC gamma gene. This insertion created additional binding sites for Sp1 and Oct-1. Five and three Brown Norway polymorphic sites were lost in Dahl and Wistar rats, respectively. No sequence variability in ENaC 3' flanking regions was identified in Dahl compared to Brown Norway rats.
  
  
  CONCLUSIONS
  The first comprehensive sequence analysis of ENaC genes did not reveal any differences between Dahl S and R rats that were isogenic in the regions screened. Mutations in ENaC genes intronic sequence or in ENaC-regulatory genes might possibly account for increased ENaC activity in Dahl S versus R rats.
authors.affiliation: Laboratory of Genetics of Cardiac Diseases, University of Ottawa Heart Institute, Ottawa, ON, Canada. mshehata@ottawaheart.ca <mshehata@ottawaheart.ca>
authors.forename: Marlene F
authors.initials: MF
authors.lastname: Shehata
authors.forename: Frans H H
authors.initials: FH
authors.lastname: Leenen
authors.forename: Frédérique
authors.initials: F
authors.lastname: Tesson
mesh_terms: D024509:3' Flanking Region / Q000235:genetics*; D024506:5' Flanking Region / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D017931:DNA Primers; D053503:Epithelial Sodium Channels / Q000235:genetics*; D008297:Male; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D051381:Rats; D020303:Rats, Inbred Dahl; D017208:Rats, Wistar; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D053503:Epithelial Sodium Channels