Kim / Poster

Phylogeny and evolution of retro-elements in humans and apes

Kim H.-S.1, Takenaka O.2, Hyun B.-H.3, Choi J.-Y.1, and Crow T.J.4
1. Section of Biological System, Division of Biological Science, Pusan National University, Pusan, Korea 2. Dept. of Molecular Biology, Primate Research Institute, Kyoto University, Inuyama, Japan 3. Genetic Resources Center, Korea Research Institute of Biological and Biotechnology, Taejeon, Korea 4. POWIC, Dept. of Psychiatry, Warneford Hospital, University of Oxford, Oxford, U.K.

     The possibility that retroviruses and retroposons contribute to genome plasticity and evolution has been widely considered but such elements are numerous and the vast majority must be unrelated to functional genes. We propose a strategy for identifying those elements that might have exerted an influence on the course of human evolution. Between the separation of the hominid and chimpanzee lineages a 4Mb block in Xq21.3 transposed to Yp and was subsequently split by a paracentric inversion(Sargent et al., 1996). The sequences on the Y are thus human specific and such genes as they may include are subject to mew evolutionary pressures, including sexual selection (Crow, 1998). Within the Xq21.3/Yp region of homology by the use of a PCR-based phylogenetic approach we have identified two classes of element that are Homo sapiens specific: i) two representatives (HS307 and 408) of the class of SINE-R elements that have been derived from the HERV-K (human endogenous retrovirus-K) genome, and ii) two HERV-K LTR sequences that belong to Medstrand and Mager's (1998) human-specific cluster 9. Each of these classes of element has proliferated since the separation of the chimpanzee and hominid lineages and these particular elements have done so in a region of the genome that has been subject to discontinuous change within that period of evolutionary time. If retro-elements have influenced the course of human evolution such representatives are candidates and this strategy provides a means by which the relevant genes, if they exist, may be identified.