Isochores : isochores have been studied for a long time; recently the research group has made very significant progress towards understanding this phenomenon. The two most important results are 1) G+C-isochores are not at evolutionary equilibrium: we have shown that they tend to disappear at least in primates and in artiodactyls. 2) Isochores are likely created by a phenomenon called "biased gene conversion" (BGC) that tends to increase the G+C content of sequences located in regions of high recombination rate. This is a neutral phenomenon driven by the mechanics of genome replication rather than by adaptive selection.
Chirochores : the research group has been among the discoverers of this phenomenon. Recent contributions are: 1) a software for the identification of chirochores, and of the origin and terminus of DNA replication in bacterial genomes. 2) Progress in analysis of the mechanism at their origin: observed effects in bacterial genome sequences are almost universal and are compatible in most cases with the hypothesis of an excess of cytosine deamination in the single-stranded state during DNA replication.
Transposable elements: transposons but not retrotransposons are located preferentially in regions of high recombination rate in Caenorhabditis elegans.