The effect of genomic location on molecular evolution and variation

Professor B. Charlesworth

Data from a number of systems indicate that molecular variation and the overall level of adaptation are reduced in regions of the genome where genetic recombination is reduced or absent. An extreme example of the latter is provided by the degeneration of Y chromosomes. A variety of population genetic processes have been invoked to account for this observations; these involve a number of different ways in which selection at one locus can affect the behaviour of a closely-linked locus (hitch-hiking). A major challenge is to develop testable predictions of the effects of the different processes on patterns of molecular variation and evolution, and to apply these to data on DNA sequences from natural systems. For this purpose, we are investigating systems such as the relatively new neo-Y chromosomes of some Drosophila species, and non-recombining chromosomal regions in Drosophila. Both theoretical and empirical approaches to these questions are being pursued.

References

Bachtrog D, and Charlesworth B (2000) Reduced variability on the neo-Y chromosome of Drosophila miranda. Curr. Biol. 10: 1025-1031.

Gordo, I and Charlesworth B (2000) The degeneration of haploid populations and the speed of MullerÕs ratchet. Genetics 154: 1379-1387.

McVean, G A T and B Charlesworth (2000) The effects of Hill-Robertson interference betwen weakly selected mutations on patterns of molecular evolution and variation. Genetics 155: 929-944.