Nucleo-cytoplasmic shuttling of splicing factor SRSF1 is required for development and cilia function

Shuttling RNA-binding proteins coordinate nuclear and cytoplasmic steps of gene expression. The SR family proteins regulate RNA splicing in the nucleus and a subset of them, including SRSF1, shuttles between the nucleus and cytoplasm affecting post-splicing processes. However, the physiological significance of this remains unclear. Here, we used genome editing to knock-in a nuclear retention signal (NRS) in Srsf1 to create a mouse model harboring an SRSF1 protein that is retained exclusively in the nucleus. Srsf1NRS/NRS mutants displayed small body size, hydrocephalus, and immotile sperm, all traits associated with ciliary defects. We observed reduced translation of a subset of mRNAs and decreased abundance of proteins involved in multiciliogenesis, with disruption of ciliary ultrastructure and motility in cells and tissues derived from this mouse model. These results demonstrate that SRSF1 shuttling is used to reprogram gene expression networks in the context of high cellular demands, as observed here, during motile ciliogenesis

Interplay between elastic instabilities and shear-banding: three categories of Taylor–Couette flows and beyond

In the past twenty years, shear-banding flows have been probed by various techniques, such as rheometry, velocimetry and flow birefringence. In micellar solutions, many of the data collected exhibit unexplained spatiotemporal fluctuations. Recently, it has been suggested that those fluctuations originate from a purely elastic instability of the shear-banding flow. In cylindrical Couette geometry, the instability is reminiscent of the Taylor-like instability observed in viscoelastic polymer solutions. The criterion for purely elastic Taylor–Couette instability adapted to shear-banding flows suggested three categories of shear-banding depending on their stability. In the present study, we report on a large set of experimental data which demonstrates the existence of the three categories of shear-banding flows in various surfactant solutions. Consistent with theoretical predictions, increases in the surfactant concentration or in the curvature of the geometry destabilize the flow, whereas an increase in temperature stabilizes the flow. However, experiments also exhibit some interesting behaviors going beyond the purely elastic instability criterion.National Science Foundation (U.S.). Graduate Research Fellowship Progra

Translations from Greek and Latin classics, Part 1: 1550–1700: a revised bibliography

This is the first instalment of a two-part revision of the classical translation sections of the second edition of The Cambridge Bibliography of English Literature, Vols 2–3. The recent discontinuation of the revised edition of CBEL deprives the scholarly world of an up-to-date version of the most complete bibliography of its kind; this contribution makes good that loss for this topic. Over its eventual two parts 1550–1800 it runs to some 1,500 items of translation for what might be held to constitute the golden age of the English classical translating tradition. Checking of existing entries in the listings has led to a large number of internal corrections, including deletions, but the records have been expanded by a net 20%, with several minor classical authors added. As compared to the previous CBEL editions of the 1940s, this reflects the availability of digital-era resources such as the English Short Title Catalogue

Choosing the future of Antarctica

We present two narratives on the future of Antarctica and the Southern Ocean, from the perspective of an observer looking back from 2070. In the first scenario, greenhouse gas emissions remained unchecked, the climate continued to warm, and the policy response was ineffective; this had large ramifications in Antarctica and the Southern Ocean, with worldwide impacts. In the second scenario, ambitious action was taken to limit greenhouse gas emissions and to establish policies that reduced anthropogenic pressure on the environment, slowing the rate of change in Antarctica. Choices made in the next decade will determine what trajectory is realized