TY - JOUR
T1 - Comparative analysis of intra-individual and inter-species DNA sequence variation in salmonid ribosomal DNA cistrons
AU - Reed, Kent M.
AU - Hackett, Jeremiah D.
AU - Phillips, Ruth B.
N1 - Funding Information:
This research was supported by grants from the US National Science Foundation (DEB-9707468) and the Research Experience for Undergraduates (REU) program.
PY - 2000/5/16
Y1 - 2000/5/16
N2 - This study examines sequence divergence in three spacer regions of the ribosomal DNA (rDNA) cistron, to test the hypothesis of unequal mutation rates. Portions of two transcribed spacers (ITS-1 and 5' ETS) and the non-transcribed spacer (NTS) or intergenic spacer (IGS) formed the basis of comparative analyses. Sequence divergence was measured both within an individual lake trout (Salvelinus namaycush) and among several related salmonid species (lake trout; brook trout, Salvelinus fontinalis; Arctic char, Salvelinus alpinus; Atlantic salmon, Salmo salar; and brown trout, Salmo trutta). Despite major differences in the length of the rDNA cistron within individual lake trout, minimal sequence difference was detected among cistrons. Interspecies comparisons found that molecular variation in the rDNA spacers did not conform to the predicted pattern of evolution (ITS spacers<ETS spacers<IGS). Specifically, the IGS contains a region that appears to be as highly, or more conserved than the ITS-1.
AB - This study examines sequence divergence in three spacer regions of the ribosomal DNA (rDNA) cistron, to test the hypothesis of unequal mutation rates. Portions of two transcribed spacers (ITS-1 and 5' ETS) and the non-transcribed spacer (NTS) or intergenic spacer (IGS) formed the basis of comparative analyses. Sequence divergence was measured both within an individual lake trout (Salvelinus namaycush) and among several related salmonid species (lake trout; brook trout, Salvelinus fontinalis; Arctic char, Salvelinus alpinus; Atlantic salmon, Salmo salar; and brown trout, Salmo trutta). Despite major differences in the length of the rDNA cistron within individual lake trout, minimal sequence difference was detected among cistrons. Interspecies comparisons found that molecular variation in the rDNA spacers did not conform to the predicted pattern of evolution (ITS spacers<ETS spacers<IGS). Specifically, the IGS contains a region that appears to be as highly, or more conserved than the ITS-1.
KW - Intergenic spacer (IGS)
KW - Molecular evolution
KW - Ribosomal DNA (rDNA)
KW - Salmon
KW - Trout
UR - http://www.scopus.com/inward/record.url?scp=0034673926&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034673926&partnerID=8YFLogxK
U2 - 10.1016/S0378-1119(00)00156-6
DO - 10.1016/S0378-1119(00)00156-6
M3 - Article
C2 - 10831845
AN - SCOPUS:0034673926
SN - 0378-1119
VL - 249
SP - 115
EP - 125
JO - Gene
JF - Gene
IS - 1-2
ER -