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Biology subjects

Gunn, J. S.

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

2 recordsLinked to original sources

Integrating carbon stocks and wildlife connectivity for nature-based climate solutions

Actions to protect against biodiversity loss and climate change will require a framework that addresses synergies between these interrelated issues. In this study we present methods for identifying areas important for the implementation of nature-based climate solutions and biodiversity conservation by intersecting high resolution spatial data for carbon storage and terrestrial connectivity. We explored the spatial congruence of carbon and connectivity in Ontario, Canada and examined effectiveness of current protected areas coverage. We found a weak positive relationship between carbon stocks and terrestrial connectivity; however, our maps revealed large hotspots, with high values of both indices, throughout the boreal forest and northern peatlands and smaller, isolated hotspots in the settled landscapes of the south. Location of hotspots varied depending on whether we considered forest or soil carbon. Further, our results show that current protected and conserved areas in Ontario only cover 13% of landscapes with the highest values for both carbon storage and connectivity. Protection or restoration of areas that maximize the co-benefits of carbon storage and connectivity would make significant contributions towards ambitious national targets to reduce greenhouse gas emissions and conserve biodiversity.

ecology↗

High-throughput discovery of peptide activators of a bacterial sensor kinase

Bacteria use two-component system (TCS) signaling pathways to sense and respond to peptides involved in host defense, quorum sensing, and inter-bacterial warfare. However, little is known about the peptide-sensing capabilities of these TCSs. Here, we develop a high-throughput E. coli display method to characterize the effects of human antimicrobial peptides (AMPs) on the pathogenesis-regulating TCS PhoPQ of Salmonella Typhimurium. We find that PhoPQ senses AMPs comprising diverse sequences, structures, and biological functions. Using thousands of AMP variants, we identify sub-domains and biophysical features responsible for PhoPQ activation. We show that most of the newfound activators induce PhoPQ in S. Typhimurium, suggesting a role in virulence regulation. Finally, we find that PhoPQ homologs from Klebsiella pneumoniae and extraintestinal pathogenic E. coli, which occupy different in vivo niches, exhibit distinct AMP response profiles. Our high-throughput method enables new insights into the specificities, mechanisms, and evolutionary dynamics of TCS-mediated peptide sensing in bacteria.

synthetic biology↗