Biology subjects

Thornton, S. J.

Publications and source records attributed to Thornton, S. J..

3 recordsLinked to original sources

bioRxiv2026

Breath to genome: Whole genome sequencing of large whales from blow sampling

Preserving biodiversity requires the genetic monitoring of wild populations, but traditional invasive sampling techniques can impact animal welfare. For cetaceans, a promising non-invasive approach is the collection of exhaled respiratory vapour, or blow, to generate individual genetic profiles. Here, we demonstrate the feasibility of generating whole genomes from the blow of humpback whales with data of sufficient quality for population genomics. A total of 58 blow samples from 26 Northeast Pacific humpback whales (Megaptera novaeangliae) were collected in Gitgaat First Nation territory using a commercially available drone. The high endogenous content at 84% on average allowed us to generate low-coverage nuclear genomes (mean 2.3x, range 0.2x-3.5x) and high coverage mitochondrial genomes (mean 94x, range 7.7x-151.3x) for inference of population structure, diversity and phylogenomics. The reliability of the blow-derived genomes was demonstrated by direct comparison between replicate blow samples, as well as paired tissue samples from a subset of individuals.

genomics↗

bioRxiv2026

Partition Coefficients Reveal Changes in Properties of Low-Contrast Biomolecular Condensates

Biomolecular condensates are domains within cells with distinct compositions, held together by intermolecular cohesion. They are implicated in a variety of cellular processes, and in vitro studies have revealed the molecular driving forces that underly their condensation. However, in vitro condensates do not capture essential features of cellular condensates. In particular, enrichment of proteins, quantified by partition coefficients, is often exaggerated in these simplified systems. We show that the addition of free amino acids and other small molecules to model condensates can bring their partition coefficients within physiological range. In this limit, where there is low biochemical contrast between condensates and their surroundings, we observe striking changes to condensate behavior. Such low-contrast condensates exhibit large fluctuations in shape and composition and show enhanced sensitivity to changes in their environment. These behaviors reflect dramatic shifts to their material properties, including interfacial tension, rheology, and chemical susceptibilities. We note remarkable similarities in these effects across seemingly unrelated two-phase fluid systems. To explain these trends, we reformulate classic models of critical phenomena in terms of partition coefficients. This framework simplifies application of theory to experiments with near-critical fluids and suggests new experimental approaches for assessing condensate physiology in live cells.

biophysics↗

bioRxiv2025

Fifteen-year microbiome survey of endangered killer whales (Orcinus orca) reveals declining diversity and population differences

The endangered Southern Resident killer whale (Orcinus orca) (SRKW) population is burdened by multiple anthropogenic stressors with limited non-invasive approaches for health surveillance. The gut microbiome is interconnected with host physiology and can be characterized using remotely collected fecal samples, creating unique opportunities to integrate environmental and individualized host-associated features of health. In this study, we used fecal samples collected over a 15-year period (2005-2019) from 77% of the living, wild SRKW population (56 individuals, 1-17 time points per individual), as well as fecal samples from the conspecific Northern and Alaska Resident killer whale populations, to characterize distal gut microbiota structure and genomic composition. SRKW microbiotas were individualized and distinct from those of the nearby Northern and Alaska Resident populations, both of which exhibit consistently higher fecundity and survivorship. During the study period, SRKW fecal microbiota species richness declined, despite stability over periods of time less than or equal to 1 year. Several potential bacterial pathogens, such as Fusobacterium spp., achieved dominance in the fecal microbiotas of SRKW individuals sampled within 6 months of death. These findings demonstrate the feasibility and value of harnessing non-invasively collected fecal samples and microbiome profiles for longitudinal killer whale health surveillance.

microbiology↗