A study of chromatin mobility by live fluorescence microscopy in saccharomyces cerevisiae

In eukaryotes, the nuclear envelope separates chromosomes from the cytoplasm. Within the nucleus, chromosomes are non-randomly distributed and different chromosomal features localize to specific subnuclear compartments. This phenomenon is generally referred to as nuclear organization. Nuclear organization however is not static, but very dynamic. Here we discuss the tools and methods we developed to study the movements of chromatin in live yeast cells with high precision. We found that find that the context of the chromosomal fiber itself and chromosomal features such as telomeres and centromeres both constrain chromatin movement, whereas the chromatin state has no effect. Targeting of proteins to specific chromosomal loci was used to show that chromatin movements can be modulated. In particular targeting of the strong transcriptional activator VP16 or the catalytic subunit of a chromatin remodeling complex are sufficient to increase locus movements, suggesting that increased movement may be part of how these proteins influence nuclear functions like transcription or recombination