Hierarchical interactions between nucleolar and heterochromatin condensates are mediated by a dual-affinity protein

Nucleoli are surrounded by Pericentromeric Heterochromatin (PCH), reflecting a conserved spatial association between the two largest biomolecular condensates in eukaryotic nuclei. Nucleoli are the sites of ribosome synthesis, while the repeat-rich PCH is essential for chromosome segregation, genome stability, and transcriptional silencing, yet the mechanisms for their co-assembly are unclear. Here, we use high-resolution live imaging during Drosophila embryogenesis and reveal that de novo establishment of PCH-nucleolar associations is highly dynamic, as PCH transitions from extending along the nuclear edge to surrounding the nucleolus. Eliminating the nucleolus by removing the ribosomal RNA genes (rDNA) disrupted this process, causing increased PCH compaction followed by its reorganization into a toroidal structure. Further, in embryos lacking rDNA, nucleolar proteins were redistributed into new bodies or ‘neocondensates’, including enrichment in the PCH toroidal hole. Combining these i..., , # Hierarchical interactions between nucleolar and heterochromatin condensates are mediated by a dual-affinity protein

Dataset DOI: [10.5061/dryad.vx0k6dk59](https://doi.org/10.5061/dryad.vx0k6dk59)

## Description of the data and file structure

**Dataset Title**\
Microscopy source data for “Hierarchical interactions between nucleolar and heterochromatin condensates are mediated by a dual-affinity protein.”

**Authors**\
Srivarsha Rajshekar, Omar Adame-Arana, Gaurav Bajpai, Serafin U. Colmenares, Hannah Papoi, Lucy D. Brennan, Shingo Tsukamoto, Samuel Safran, Gary H. Karpen

**Corresponding Author Contact**\
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**First Author Contact**\
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**Dataset Overview**\
This dataset contains the source data for all the microscopy images presented in the figures of the associated publication. Data are organized by figure type (main figures and extended data figures).

**Associated Publicatio...,