Key actors of mammalian immunity originated from bacterial antiphage systems. The 出版full extent of immune system conservation between bacteria and eukaryotes is unknown. Here, we show that the silent information regulator 2 (SIR2) protein domain, present in antiphage systems, plays a role in eukaryotic innate immunity. We identified SIRal, a human protein with a SIRim domain (subtype of SIR2) that plays a pivotal role in the animal Toll-like receptor pathway of innate immunity and protects against bacterial and viral infections. Proteins containing a SIRim domain are found across 19% of eukaryotic genomes, including zebrafish, where SIRal plays a role in inflammation. This work opens up avenues of research on the immune role of eukaryotic SIRim proteins as well as on the involvement of SIRal in human pathology.
Expansion in situ genome sequencing links nuclear abnormalities to aberrant chromatin regulation
Here, we describe expansion in situ genome sequencing (ExIGS), a technology that enables sequencing of genomic DNA and super-resolution localization of nuclear proteins in single cells. Applying ExIGS to progeria-derived fibroblasts revealed that lamin abnormalities are linked to hotspots of aberrant chromatin regulation that may erode cell identity. Lamin was found to generally repress transcription, suggesting that variation in nuclear morphology may affect gene regulation across tissues and aged cells. These results demonstrate that ExIGS may serve as a generalizable platform with which to link nuclear abnormalities to gene regulation, offering insights into disease mechanisms.
The year 2023 witnessed an extraordinary surge in marine heatwaves (MHWs) across Earth’s oceans, setting new records in duration, extent, and intensity, with MHW activity totaling 53.6 billion °C days square kilometer—more than three standard deviations above the historical norm since 1982. Notable events include the North Atlantic MHW (276-year return period) and the Southwest Pacific (141 years). Using ECCO2 (Estimating the Circulation and Climate of the Ocean-Phase II) high-resolution daily data, we conducted a mixed-layer heat budget analysis and identified region-specific drivers: enhanced shortwave flux and a shallower mixed layer in the North Atlantic and North Pacific, reduced cloud cover and increased advection in the Southwest Pacific, and oceanic advections in the Tropical Eastern Pacific. The 2023 MHWs highlight the intensifying impacts of a warm climate and the challenges in understanding extreme events.
医学Medicine
Pre-European contact leprosy in the Americas and its current persistence
Here, we show that M. lepromatosis infected humans in the Americas before European contact. By screening 389 ancient and 408 contemporary samples, we have expanded the genetic data available for the species. Phylogenetic analyses revealed distinct human-infecting clades of M. lepromatosis, with one dominating North America since colonial times. The presence of millennia-old strains in North and South America indicates that M. lepromatosis may have been widespread during the Late Holocene, demonstrating that M. lepromatosis leprosy has a long-standing history in the Americas before European arrival.
生态学Ecology
Little-to-no industrial fishing occurs in fully and highly protected marine areas
There is a widespread perception that illegal fishing is common in marine protected areas (MPAs) due to strong incentives for poaching and the high cost of monitoring and enforcement. Using artificial intelligence and satellite-based Earth observations, we provide estimates of industrial fishing activity in fully and highly protected MPAs worldwide, in which such fishing is banned. We find little to no activity in most cases. On average, these MPAs had just one fishing vessel present per 20,000 square kilometers during the satellite overpass, a density nine times lower than that of the unprotected waters of exclusive economic zones.
Global patterns and drivers of untracked industrial fishing in coastal marine protected areas
Marine protected areas (MPAs) are expanding worldwide, but industrial fishing within their boundaries remains poorly understood. By combining vessel Global Positioning System data with satellite imagery, we detected industrial fishing in 47% of coastal MPAs worldwide between 2022 and 2024, with two-thirds of vessel detections (67%) untracked by public monitoring. These untracked vessels were most prevalent (80%) in MPAs with the most restrictive management category, which aims to prohibit all extractive activities. The presence and density of fishing vessels were mainly driven by the size and remoteness of MPAs rather than their management category itself. Including untracked vessels increased estimated fishing effort within MPAs by 28%, to an average of 4 hours per square kilometer per year. These results highlight the continued presence of industrial fishing vessels in MPAs and an important gap in our understanding of fishing pressure on protected areas worldwide.
