Abstract # 5952 Event # 12:

Scheduled for Saturday, September 13, 2014 01:30 PM-01:45 PM: Session 4 (Decatur A) Oral Presentation


ANCESTRAL ADH4 ENZYMES INDICATE THE ANCESTORS OF HUMANS (HOMO SAPIENS) AND GORILLAS (GORILLA GORILLA GORILLA) ADAPTED TO FERMENTED FRUIT.

M. Carrigan1, O. Uryasev2, C. B. Frye2, C. R. Myers3, T. D. Hurley3 and S. A. Benner2
1Department of Natural Sciences, Santa Fe College, 3000 NW 83 Street, Gainesville, FL 32606, USA, 2Foundation for Applied Molecular Evolution, P.O. Box 13174, Gainesville, FL 32604, 3Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
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     Many modern human diseases are attributed to an incompatibility between our current environment and the environment for which our genome is adapted. This model has been applied to alcoholism, positing that human predisposition towards ethanol consumption arises from our evolution as a highly frugivorous primate. We tested this hypothesis by examining the evolution of alcohol dehydrogenase class IV (ADH4), the first enzyme exposed to dietary ethanol in the upper gastrointestinal tract. The sequences of ADH4 genes from seventeen primates (G.moholi, D.madagascariensis, E.albifrons, M.murinus, T.syrichta, S.sciureus, C.apella, S.oedipus, C.jacchus, C.aethiops, M.mulatta, P.anubis, N.leucogenys, P.pygmaeus, G.gorilla, P.troglodytes, H.sapiens) were used to infer the sequences of ancestral ADH4s at various points during the past 70 million years of primate evolution. We resurrected several ancestral ADH4 enzymes from different points during this period, and identify a single mutation occurring in the ancestor of African apes that endowed this ancestor with a markedly enhanced ability to metabolize ethanol (as measured by changes in the kcat/Km values, p < 0.05, Welch’s t-test). This genetic change coincides in time with when the ancestors of African apes adopted a terrestrial lifestyle. Since fruit collected from the ground is more likely to be infected by fermenting yeast than hanging fruit, this novel form of ADH4 may have provided an advantage to primates living where fermented fruit is more common.