Biology subjects

Schroeter, S.

Publications and source records attributed to Schroeter, S..

4 recordsLinked to original sources

bioRxiv2025

Effects of wasting disease on sea star populations in southern California: Variations over a 40-year period

Sea star wasting disease has been described for asteroid populations from many parts of the world and for numerous species. The causative agents are generally unknown. However, within the Southern California Bight, a Vibrio bacterium appears to have been the cause of wasting disease in the 1980s, and probably the 1990s, during warm water episodes associated with El Ninos. Although a densovirus was implicated in the mass mortality of one species of subtidal sea star during the geographically widespread epizootics that began in 2013, the etiology appears to vary among species, locations, and time periods, and in some cases may not even be associated with a pathogen. We have been studying subtidal benthic communities in southern California since the 1970s and have documented the population effects of wasting disease epizootics associated with warm water El Nino events from 1980 through 2020. Until 2015, population declines coincident with wasting disease were followed by various degrees of recovery, whereas after 2015 there has been little or no recovery at our study sites. Prior to 2013, wasting disease in the northeast Pacific was only reported from locations in the Gulf of California, the southern California bight, and the coast of Vancouver Island, British Columbia. Since 2013, epizootics of wasting disease among sea stars have been observed along the entire west coast of North America. We speculate that the lack of recovery after 2015 may be due to a reduction in larval supply caused by the greater geographical extent of the disease.

ecology↗

bioRxiv2024

TDP-43 pathology links innate and adaptive immunity in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is the most common fatal motor neuron disease. Approximately 90% of ALS patients exhibit pathology of the master RNA regulator, Transactive Response DNA Binding protein (TDP-43). Despite the prevalence TDP-43 pathology in ALS motor neurons, recent findings suggest immune dysfunction is a determinant of disease progression in patients. Whether TDP-43 pathology elicits disease-modifying immune responses in ALS remains underexplored. In this study, we demonstrate that TDP-43 pathology is internalized by antigen presenting cells, causes vesicle rupture, and leads to innate and adaptive immune cell activation. Using a multiplex imaging platform, we observed interactions between innate and adaptive immune cells near TDP-43 pathological lesions in ALS brain. We used a mass cytometry-based whole-blood stimulation assay to provide evidence that ALS patient peripheral immune cells exhibit responses to TDP-43 aggregates. Taken together, this study provides a novel link between TDP-43 pathology and ALS immune dysfunction, and further highlights the translational and diagnostic implications of monitoring and manipulating the ALS immune response.

cell biology↗

bioRxiv2023

Thermal suppression of gametogenesis explains historical collapses in larval recruitment

Projections for population viability under climate change are often made using estimates of thermal lethal thresholds. These estimates vary across life history stages and can be valuable for explaining or forecasting shifts in population viability. However, sublethal temperatures can also depress vital rates and shape fluctuations in the reproductive viability of populations. For example, heatwaves may suppress reproduction, leading to recruitment failure before lethal temperatures are reached. Despite a growing awareness of this issue, tying sublethal effects to observed recruitment failure remains a challenge especially in marine environments. We experimentally show that sublethal suppression of female gametogenesis by marine heatwaves can partially explain historical collapses in urchin recruitment. This response differed by sex but was similar between animals from warmer or cooler regions of their range. Overall, we show sublethal thermal sensitivities of reproduction can narrow the thermal envelope for population viability compared to predictions from lethal limits.

ecology↗

bioRxiv2019

Biophysical characterization of DNA origami nanostructures reveals inaccessibility to intercalation binding sites

Intercalation of drug molecules into synthetic DNA nanostructures formed through self-assembled origami has been postulated as a valuable future method for targeted drug delivery. This is due to the excellent biocompatibility of synthetic DNA nanostructures, and high potential for flexible programmability including facile drug release into or near to target cells. Such favourable properties may enable high initial loading and efficient release for a predictable number of drug molecules per nanostructure carrier, important for efficient delivery of safe and effective drug doses to minimise non-specific release away from target cells. However, basic questions remain as to how intercalation-mediated loading depends on the DNA carrier structure. Here we use the interaction of dyes YOYO-1 and acridine orange with a tightly-packed 2D DNA origami tile as a simple model system to investigate intercalation-mediated loading. We employed multiple biophysical techniques including single-molecule fluorescence microscopy, atomic force microscopy, gel electrophoresis and controllable damage using low temperature plasma on synthetic DNA origami samples. Our results indicate that not all potential DNA binding sites are accessible for dye intercalation, which has implications for future DNA nanostructures designed for targeted drug delivery.

biophysics↗