The role of insulators and transcription in 3D chromatin organization of flies.

The DNA in many organisms, including humans, is shown to be organized in topologically associating domains (TADs). In , several architectural proteins are enriched at TAD borders, but it is still unclear whether these proteins play a functional role in the formation and maintenance of TADs. Here, we show that depletion of BEAF-32, Cp190, Chro, and Dref leads to changes in TAD organization and chromatin loops.

Chromatin architecture reorganization during neuronal cell differentiation in genome.

The organization of the genome into topologically associating domains (TADs) was shown to have a regulatory role in development and cellular function, but the mechanism involved in TAD establishment is still unclear. Here, we present the first high-resolution contact map of neuronal cells (BG3) and identify different classes of TADs by comparing this to genome organization in embryonic cells (Kc167). We find that only some TADs are conserved in both cell lines, whereas the rest are cell-type-specific.

A splicing-dependent transcriptional checkpoint associated with prespliceosome formation.

There is good evidence for functional interactions between splicing and transcription in eukaryotes, but how and why these processes are coupled remain unknown. Prp5 protein (Prp5p) is an RNA-stimulated adenosine triphosphatase (ATPase) required for prespliceosome formation in yeast. We demonstrate through in vivo RNA labeling that, in addition to a splicing defect, the prp5-1 mutation causes a defect in the transcription of intron-containing genes.

Identification of a novel nucleolin related protein (NRP) gene expressed during rat spermatogenesis.

Background: Nucleolin is a major nucleolar phosphoprotein involved in various steps of ribosome biogenesis in eukaryotic cells. As nucleolin plays a significant role in ribosomal RNA transcription we were interested in examining in detail the expression of nucleolin across different stages of spermatogenesis and correlate with the transcription status of ribosomal DNA in germ cells.

Results: By RT PCR and western blot analysis we found that nucleolin is strongly down regulated in meiotic spermatocytes and haploid germ cells.