Month: October 2024

This artist’s impression of a planet-forming disk surrounding a young star shows a swirling “pancake” of hot gas and dust from which planets form. Using the James Webb Space Telescope, a team of researchers obtained detailed images showing the layered, conical structure of disk winds – streams of gas blowing out into space. National Astronomical Observatory of Japan (NAOJ)

Using data from NASA’s James Webb Space Telescope (JWST), researchers such as Clemson University’s Sean Brittain captured the most detailed images yet of protoplanetary disk winds—streams of gas that shape the disks where planets form. These winds may solve the mystery of how disks lose angular momentum, enabling gas to accrete onto young stars much faster than previously thought. The study, published in Nature Astronomy, observed four protoplanetary disk systems: a complex, three-dimensional structure of winds originating from different regions of the disk, which resembles a layered onion.

The findings provide the first tangible evidence supporting the theory that magnetic field-driven winds play a key role in star growth and disk evolution. Thermal winds and X-winds also contribute. By tuning JWST’s detectors to specific molecules, the team traced the layers of these winds and discovered a central hole in the cone-shaped structures, formed by molecular winds. These insights could refine our understanding of planet formation and stellar evolution. The researchers now plan to expand their observations to more disks to deepen their knowledge.

Credit: David Brandin

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James Webb Space Telescope reveals evidence of winds that could solve mystery of how planet-forming disks are shaped | Clemson News

Clemson University researchers, led by Laura Finzi, have uncovered the role of mechanical forces in gene transcription, specifically in RNA polymerase (RNAP) activity during termination. While the traditional view holds that RNAP dissociates from DNA after releasing mRNA, the team demonstrated that force can cause RNAP to slide forward or backward on the DNA template. This force-directed recycling allows genes to be transcribed multiple times or only once, affecting gene expression.

Using magnetic tweezers, the researchers found that RNAP’s ability to switch to oppositely oriented promoters relies on the C-terminal domains of its alpha subunits. Deleting these subunits prevents RNAP from flipping to oppositely oriented promoters. Published in Nature Communications, these findings could inform strategies for regulating transcription and suppressing harmful proteins. Finzi envisions a future where a map of forces on the genome helps predict transcription levels across genes and cells. The study was supported by NIH grants.

Credit: David Brandin

Read more here: 
Research provides new insights into role of mechanical forces in gene expression | Clemson News