Genome sequences: experimental determination and evolutionary interpretation

The genome project is an interdisciplinary effort to determine and analyze the sequences of whole genomes. Laboratory techniques presented here may contribute to this effort. One of these techniques involves the use of enzyme-linked fluorescence for detection of DNA on membranes in hybridization experiments. This technique facilitates the automation of hybridization experiments. Another technique involves the use of modified primers in cycle sequencing reactions to eliminate artifacts and improve sequence determination. Introduction of residues into the primer that can not be replicated by DNA polymerase eliminates the possibility of unwanted exponential amplification of side-products. The sequence of the genome of the hypothermophilic archaeon Pyrococcus furiosus, along with the other microbial gnome sequences becoming ailable, has been the basis of inquiries concerning the evolution of histidine biosynthetic operons and the biochemistry and evolution of inteins. These studies provide evidence of lateral transfer of genetic material and recruitment of genes to new functions. Theoretical work is presented concerning the process by which sequences change over evolutionary time. A model is presented that predicts approximate independence of the rate of change from the effective population size, contrary to the accepted understanding of the nearly neutral theory of molecular evolution.