The Upright Ape: A New Origin of the Species

by Aaron G. Filler, MD, PhD

Figure 6-3 Cation Alterations of DNA/RNA Polymerases may Explain the Cambrian Explosion

Processivity Modification by Cation Substitution

Figure 6-3 – Modification of Mutability by Environmental Factors

The  rapidly evolving HIV genome demonstrates environmental effects on rate of mutation.

A – The speed of reverse transcription from RNA to DNA is affected by the concentration of various elements in the medium.

B – The polymerase enzyme produces fragments of the genome with standardized breakpoints sorted out by length in electrophoretic gel. Some elements cause improved readthrough – longer segments of DNA so that certain bands disappear in some channels.

C – RNA has a 3D structure of  hairpins and loops. Breakpoints correspond to geometric twists and turns of the RNA.

D – HIV genome shows high rates of transcript breakage at loops and bends.

Figure credits -

A - From: Filler, A.G. and A. M. L. Lever (1996). Nucleic acid amplification using scandium and lanthanum ions. US Patent 5,554,498. and - Filler, A. G. and A. M. Lever (1997). Effects of cation substitutions on reverse transcriptase and on human immunodeficiency virus production. AIDS Research and Human Retroviruses 13(4): 291-9.

B - From: Filler, A. G. and A. M. L. Lever (2007). Molecular evidence for environmental trigger of mass evolutionary acceleration: an experimental model for the Cambrian Explosion. American Association for the Advancement of Science, Pacific Division. Boise, Idaho.

C - From: Alberts, B. (2002). Molecular Biology of the Cell. New York, Garland Science. Drawing reproduced by permission Garland Science, Taylor & Francis.

D - Redrawn, modified, after: Harrison, G. P., M. S. Mayo, E. Hunter, A.M.L. Lever. (1998). Pausing of reverse transcriptase on retroviral RNA templates is influenced by secondary structures both 5' and 3' of the catalytic site. Nucleic Acids Research 26(14): 3433-42.

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