Dynamics of nuclear compartments in C. elegans

Resumen del póster presentado al 19th International C. elegans Meeting, celebrado en Los Angeles, California (US) del 26 al 30 de junio de 2013.During development and differentiation, the genome gets progressively organized inside the nuclear space. The function of genome nuclear organization remains elusive, although a number of human diseases are linked to mutations in structural elements of the nucleus. Decreasing mobility of chromatin and chromatin factors moreover correlates with loss of differentiation potential, suggesting chromatin plasticity could be an integral part of pluripotency. Similarly to mammalian cells, the worm genome gets partitioned during cell fate acquisition into active and silent domains inside the nuclear space. In C. elegans current data suggest that the nuclear interior is a rather active domain, while the nuclear periphery is a mosaic of active and silent compartments. The dynamics of these domains during physiological challenges, cell fate determination or during organismal aging is however poorly understood. Genomic characterization of subnuclear domains has been achieved using damID, a technique in which a fusion protein between the E. coli adenine methyltransferase dam is fused to a nuclear protein specific of the nuclear compartment of interest. Adenines in genomic stretches proximal to this protein are methylated and this can be detected using microarrays or sequencing. damID has been successfully used to uncover DAF-16 target genes, but also the nuclear organization of chromosomes relative to the nuclear lamina using a dam fusion to LMN-1, the unique worm lamin. Using a newly developed methylated adenine binder, we are now able to track in vivo nuclear compartments in developing and aging worms. We will present this system in the worm as well as the first results on dynamics of subnuclear compartments in aging or physiologically challenged worms.Peer Reviewe