Donald R. Forsdyke

Learn More
When transcription is to the right of the promoter, the "top," mRNA-synonymous strand of DNA tends to be purine-rich. When transcription is to the left of the promoter, the top, mRNA-template strand tends to be pyrimidine-rich. This transcription-direction rule suggests that there has been an evolutionary selection pressure for the purine-loading of RNAs.(More)
Mutations which improve the efficiency of recombination should affect either the proteins which mediate recombination or their substrate, DNA itself. The former mutations would be localized to a few sites. The latter would be dispersed. Studies of hybridization between RNA molecules have suggested that recombination may be initiated by a homology search(More)
Genes actively involved in the G0/G1 switch (G0S genes) may be differentially expressed during the lectin-induced switch of lymphocytes from the G0 to the G1 phases of the cell cycle. This paper presents studies of G0S2, a member of a set of putative G0S genes, for which cDNAs were cloned and selected on the basis of differential cDNA hybridization. G0S2(More)
The distribution of deviations from Chargaff's second parity rule was examined for overlapping sequence windows of a length (1 kb) predicted to be suitable for detecting correlations with functional features of DNA. For long genomic segments from E. coli, Saccharomyces cerevisiae, and Vaccinia virus, Chargaff differences for the W bases and/or for the S(More)
Many eukaryotic genes are split into exons and introns, the latter being removed post-transcriptionally so that only exon sequences appear in cytoplasmic RNAs. Since introns appear in both protein-encoding RNAs and non-protein-coding RNAs, they interrupt genetic information per se, not just protein-encoding information. A DNA sequence has the potential to(More)
Radio can be used as a metaphor for the transmission of information by DNA through time and space. Just as different radio transmitters broadcast at different wavelengths to prevent interference, so different biological species "broadcast" their DNAs at different (G+C)% "wavelengths" to prevent recombination. It is postulated that species differences in(More)
Nucleic acids have the potential to form in trastrand stem-loops if complementary bases are suitably located. Computer analyses of poliovirus and retroviral RNAs have revealed a reciprocal relationship between “statistically significant” stem-loop potential and “sequence variability.” The statistically significant stem-loop potential of a nucleic acid(More)
To an approximation Chargaff's rule (%A = %T; %G = %C) applies to single-stranded DNA. In long sequences, not only complementary bases but also complementary oligonucleotides are present in approximately equal frequencies. This applies to all species studied. However, species usually differ in base composition. With the goal of understanding the(More)
Chargaff's first parity rule (%A=%T and %G=%C) is explained by the Watson-Crick model for duplex DNA in which complementary base pairs form individual accounting units. Chargaff's second parity rule is that the first rule also applies to single strands of DNA. The limits of accounting units in single strands were examined by moving windows of various sizes(More)