Heat-induced gene positioning in "Caenorhabdidtis elegans" : "hsp-16" promoter drives transcription-dependent nuclear pore association

The DNA of eukaryotic cells is packaged into transcriptionally active euchromatin and repressed heterochromatin. These two chromatin types are non-randomly distributed within the nucleus. Indeed, at the nuclear periphery, heterochromatin is enriched near the nuclear lamina whereas euchromatin is found in the vicinity of nuclear pores. Interestingly, in budding yeast, several stress inducible genes interact with nuclear pores upon activation, although the relevance of this in higher eukaryotes has been unclear. In this thesis I characterise the spatial distribution of a heat shock gene (hsp16.2) in embryos of the nematode worm Caenorhabditis elegans. I find that hsp-16.2 is preferencially found at the nuclear periphery, where it interacts with the nuclear pore complex. Using two different types of ectopically integrated hsp-16.2 promoters, I investigated the molecular mechanism of the pore-gene interaction. I find that both types of transgenes show the same distribution, even though to a lesser extent. The results presented here shed light on the promoter elements and proteins essential for the perinuclear gene localisation and suggest conservation of gene-pore interactions in yeast, worm and fly.