Lake has proposed a method, which he calls “operator metrics,” for estimating branch lengths (as transversion differences) on an unrooted phylogenetic tree of nucleotide sequences. Examination of published applications of operator metrics reveals that it often assigns branch lengths that sum to less than the observed sequence differences, indicating a substantial systematic bias. The problem oc...

The existence of the A1079T transversion in the alpha1 isoform of the Na(+), K(+)-ATPase (Atp1a1) gene in Dahl salt-sensitive rat (SS/Jr) strain, discovered by Herrera and Ruiz-Opazo and proposed to underlay hypertension sensitivity, represents one of the most controversial topics in hypertension research. As our research group did not have any previous connection to any party in this dispute n...

beta-Lactamase gene promoters of 45 clinical Klebsiella oxytoca isolates resistant to beta-lactams and exhibiting beta-lactamase hyperproduction differed from those in 26 susceptible strains. Direct sequencing revealed one mutation in either the -10 or -35 conserved sequences: a G-to-A transition of the fifth base (67%) or a G-to-T transversion of the first base of the -10 sequence (27%) or a T...

Hereditary fructose intolerance (HFI) is an inborn error of metabolism caused by aldolase B deficiency. The aldolase B gene has been cloned and the following mutations causing HFI have been identified: A149P (a G----C transversion in exon 5), A174D (a C----A transversion in exon 5), L288 delta C (a base pair deletion in exon 8), and N334K (a G----C transversion in exon 9). We have investigated ...

In the inbred Dahl salt-sensitive rat (SS/Jr strain), it has been proposed that a T for A transversion in the DNA sequence encoding amino acid 276 in the «1 subunit isofonn of Na,K-ATPase may impair ion transport and contribute to the pathogenesis of hypertension. This hypothesis is of major scientific interest because it represents the first attempt to explain the pathogenesis of salt-sensitiv...

The substitution rates of transitions are higher than expected by chance relative to those of transversions. Many have argued that selection disfavors transversions, as nonsynonymous transversions are less likely to conserve biochemical properties of the original amino acid. Only recently has it become feasible to directly test this selective hypothesis by comparing the fitness effects of a lar...