RNAP II antagonizes mitotic chromatin folding and chromosome segregation by condensin.

Condensin shapes mitotic chromosomes by folding chromatin into loops, but whether it does so by DNA-loop extrusion remains speculative. Although loop-extruding cohesin is stalled by transcription, the impact of transcription on condensin, which is enriched at highly expressed genes in many species, remains unclear. Using degrons of Rpb1 or the torpedo nuclease Dhp1 to either deplete or displace RNAPII on chromatin in fission yeast metaphase cells, we show that RNAPII does not load condensin on DNA.

Condensin positioning at telomeres by shelterin proteins drives sister-telomere disjunction in anaphase.

The localization of condensin along chromosomes is crucial for their accurate segregation in anaphase. Condensin is enriched at telomeres but how and for what purpose had remained elusive. Here, we show that fission yeast condensin accumulates at telomere repeats through the balancing acts of Taz1, a core component of the shelterin complex that ensures telomeric functions, and Mit1, a nucleosome remodeler associated with shelterin.

A long non-coding RNA mediates the hormone responsiveness of during male urogenital development.

The novel long non-coding RNA (lncRNA) is extraordinarily conserved in both its location (syntenic with an essential gene in anogenital patterning) and sequence. Here we show that is upregulated following the testosterone surge from the developing testis and directly interacts with positively regulating its expression. expression is suppressed by estrogen, which in turn suppresses the expression of .

RNA polymerase backtracking results in the accumulation of fission yeast condensin at active genes.

The mechanisms leading to the accumulation of the SMC complexes condensins around specific transcription units remain unclear. Observations made in bacteria suggested that RNA polymerases (RNAPs) constitute an obstacle to SMC translocation, particularly when RNAP and SMC travel in opposite directions. Here we show in fission yeast that gene termini harbour intrinsic condensin-accumulating features whatever the orientation of transcription, which we attribute to the frequent backtracking of RNAP at gene ends.

Aurora B and condensin are dispensable for chromosome arm and telomere separation during meiosis II.

In mitosis, while the importance of kinetochore (KT)-microtubule (MT) attachment has been known for many years, increasing evidence suggests that telomere dysfunctions also perturb chromosome segregation by contributing to the formation of chromatin bridges at anaphase. Recent evidence suggests that Aurora B kinase ensures proper chromosome segregation during mitosis not only by controlling KT-MT attachment but also by regulating telomere and chromosome arm separation. However, whether and how Aurora B governs telomere separation during meiosis has remained unknown.

Senataxin homologue Sen1 is required for efficient termination of RNA polymerase III transcription.

R-loop disassembly by the human helicase Senataxin contributes to genome integrity and to proper transcription termination at a subset of RNA polymerase II genes. Whether Senataxin also contributes to transcription termination at other classes of genes has remained unclear. Here, we show that Sen1, one of two fission yeast homologues of Senataxin, promotes efficient termination of RNA polymerase III (RNAP3) transcription in vivo.

The extruded non-template strand determines the architecture of R-loops.

Three-stranded R-loop structures have been associated with genomic instability phenotypes. What underlies their wide-ranging effects on genome stability remains poorly understood. Here we combined biochemical and atomic force microscopy approaches with single molecule R-loop footprinting to demonstrate that R-loops formed at the model Airn locus in vitro adopt a defined set of three-dimensional conformations characterized by distinct shapes and volumes, which we call R-loop objects.

The inner ear proteome of fish.

The mechanisms that underpin the formation, growth and composition of otoliths, the biomineralized stones in the inner ear of fish, are largely unknown, as only a few fish inner ear proteins have been reported. Using a partial transcriptome for the inner ear of black bream (Acanthopagrus butcheri), in conjunction with proteomic data, we discovered hundreds of previously unknown proteins in the otolith. This allowed us to develop hypotheses to explain the mechanisms of inorganic material supply and daily formation of growth bands.

Condensin controls cellular RNA levels through the accurate segregation of chromosomes instead of directly regulating transcription.

Condensins are genome organisers that shape chromosomes and promote their accurate transmission. Several studies have also implicated condensins in gene expression, although any mechanisms have remained enigmatic. Here, we report on the role of condensin in gene expression in fission and budding yeasts.

The Affinity of the S9.6 Antibody for Double-Stranded RNAs Impacts the Accurate Mapping of R-Loops in Fission Yeast.

R-loops, which result from the formation of stable DNA:RNA hybrids, can both threaten genome integrity and act as physiological regulators of gene expression and chromatin patterning. To characterize R-loops in fission yeast, we used the S9.6 antibody-based DRIPc-seq method to sequence the RNA strand of R-loops and obtain strand-specific R-loop maps at near nucleotide resolution.

Observations and modeling of the elastogravity signals preceding direct seismic waves.

After an earthquake, the earliest deformation signals are not expected to be carried by the fastest () elastic waves but by the speed-of-light changes of the gravitational field. However, these perturbations are weak and, so far, their detection has not been accurate enough to fully understand their origins and to use them for a highly valuable rapid estimate of the earthquake magnitude. We show that gravity perturbations are particularly well observed with broadband seismometers at distances between 1000 and 2000 kilometers from the source of the 2011, moment magnitude 9.

The loading of condensin in the context of chromatin.

The packaging of DNA into chromosomes is a ubiquitous process that enables living organisms to structure and transmit their genome accurately through cell divisions. In the three kingdoms of life, the architecture and dynamics of chromosomes rely upon ring-shaped SMC (Structural Maintenance of Chromosomes) condensin complexes. To understand how condensin rings organize chromosomes, it is essential to decipher how they associate with chromatin filaments.

Prompt gravity signal induced by the 2011 Tohoku-Oki earthquake.

Transient gravity changes are expected to occur at all distances during an earthquake rupture, even before the arrival of seismic waves. Here we report on the search of such a prompt gravity signal in data recorded by a superconducting gravimeter and broadband seismometers during the 2011 Mw 9.0 Tohoku-Oki earthquake.

Nucleosome eviction in mitosis assists condensin loading and chromosome condensation.

Condensins associate with DNA and shape mitotic chromosomes. Condensins are enriched nearby highly expressed genes during mitosis, but how this binding is achieved and what features associated with transcription attract condensins remain unclear. Here, we report that condensin accumulates at or in the immediate vicinity of nucleosome-depleted regions during fission yeast mitosis.

TIF1γ Suppresses Tumor Progression by Regulating Mitotic Checkpoints and Chromosomal Stability.

The transcription accessory factor TIF1γ/TRIM33/RFG7/PTC7/Ectodermin functions as a tumor suppressor that promotes development and cellular differentiation. However, its precise function in cancer has been elusive. In the present study, we report that TIF1γ inactivation causes cells to accumulate chromosomal defects, a hallmark of cancer, due to attenuations in the spindle assembly checkpoint and the post-mitotic checkpoint.

Does transcription play a role in creating a condensin binding site?

The highly conserved condensin complex is essential for the condensation and integrity of chromosomes through cell division. Published data argue that high levels of transcription contribute to specify some condensin-binding sites on chromosomes but the exact role of transcription in this process remains elusive. Here we discuss our recent data addressing the role of transcription in establishing a condensin-binding site.

RNA processing factors Swd2.2 and Sen1 antagonize RNA Pol III-dependent transcription and the localization of condensin at Pol III genes.

Condensin-mediated chromosome condensation is essential for genome stability upon cell division. Genetic studies have indicated that the association of condensin with chromatin is intimately linked to gene transcription, but what transcription-associated feature(s) direct(s) the accumulation of condensin remains unclear. Here we show in fission yeast that condensin becomes strikingly enriched at RNA Pol III-transcribed genes when Swd2.

Marker genes identify three somatic cell types in the fetal mouse ovary.

The two main functions of the ovary are the production of oocytes, which allows the continuation of the species, and secretion of female sex hormones, which control many aspects of female development and physiology. Normal development of the ovaries during embryogenesis is critical for their function and the health of the individual in later life. Although the adult ovary has been investigated in great detail, we are only starting to understand the cellular and molecular biology of early ovarian development.

CPF-associated phosphatase activity opposes condensin-mediated chromosome condensation.

Functional links connecting gene transcription and condensin-mediated chromosome condensation have been established in species ranging from prokaryotes to vertebrates. However, the exact nature of these links remains misunderstood. Here we show in fission yeast that the 3' end RNA processing factor Swd2.

Loss of function mutation in the palmitoyl-transferase HHAT leads to syndromic 46,XY disorder of sex development by impeding Hedgehog protein palmitoylation and signaling.

The Hedgehog (Hh) family of secreted proteins act as morphogens to control embryonic patterning and development in a variety of organ systems. Post-translational covalent attachment of cholesterol and palmitate to Hh proteins are critical for multimerization and long range signaling potency. However, the biological impact of lipid modifications on Hh ligand distribution and signal reception in humans remains unclear.