Condensin II function and the interphase genome
Condensins and related proteins are ring-shaped architectural proteins that are highly conserved and found from bacteria to humans. They are known for their roles in mitotic genome compaction (Condensin I and Condensin II) and sister chromatid cohesion (Cohesin). Condensin II also plays essential roles in interphase genome organization and genome stability (Rosin et al., 2018, PLOS Genetics; Rosin et al., 2019, ELife).
An unexpected role of Condensin II is that it antagonizes interactions between homologous chromosomes (maternal and paternal copies; Joyce et al., 2012; 2016) in somatic cells in Drosophila. Our lab is investigating whether this function of Condensin II is conserved across species and furthermore, we are interrogating potential roles of Condensin II in the regulation of meiotic homolog pairing.
Shown above: 5-color FISH in two nuclei from Drosophila Kc cells labeled with chromosome arm-specific Oligopaints (X in green, 2L in yellow, 2R in magenta, 3L in red, 3R in cyan. Left: control nucleus. Right: Condensin II-depleted nucleus. Gaps in the circular nuclei (particularly obvious in the Condensin II RNAi cell) are indicative of repetitive heterochromatin and the nucleolus (which are not labeled by Oligopaints here).