Biology subjects

Lacey, C.

Publications and source records attributed to Lacey, C..

3 recordsLinked to original sources

bioRxiv2024

Species-specific interactions with apex carnivores yield unique benefits and burdens for mesocarnivores

Mesocarnivores navigate a complex risk-reward continuum in ecosystems shared with their apex counterparts, balancing scavenging opportunities with risks of mortality. However, the risks to mesocarnivores in multi-carnivore systems are not uniform--often varying with specific apex-meso pairings. Using camera traps and GPS-telemetry, we examined space-use, temporal activity, fine-scale interactions, and scavenging behavior of apex (wolves, cougars) and mesocarnivores (red foxes, coyotes) in northern Yellowstone National Park, USA. Coyote space use was positively linked to wolf presence, while red fox space use was positively linked to cougar presence. Notably, photo-detection rates of mesocarnivores doubled within 24 hours of apex carnivore detections--except for coyotes following cougars. Coyotes were more frequent scavengers at wolf and cougar kills than red foxes, but they also suffered the highest mortality rates. Over 60% of wolf caused coyote mortalities were linked to wolf kill-sites, though wolves rarely consumed the coyotes themselves. In contrast, cougars hunted and consumed coyotes as prey, posing an additional risk of predation. These findings highlight how divergent hunting strategies and habitat preferences between canid and felid apex carnivores create separate risks for mesocarnivores. Our study offers new insights into the species-specific behavioral dynamics that can shape trophic interactions in multi-carnivore systems.

ecology↗

bioRxiv2020

Characterization of a new Leishmania major isolate for use in a controlled human infection model

Leishmaniasis is widely regarded as a vaccine-preventable disease, but the costs required to reach pivotal Phase 3 studies and uncertainty about which candidate vaccines should be progressed into human studies significantly limits progress in vaccine development for this neglected tropical disease. Controlled human infection models (CHIM) provide a pathway for accelerating vaccine development and to more fully understand disease pathogenesis and correlates of protection. Here, we describe the isolation, characterization and GMP manufacture of a new clinical isolate of Leishmania major. Two fresh isolates of L. major from Israel were initially compared by genome sequencing, in vivo infectivity and drug sensitivity in mice, and development and transmission competence in sand flies, allowing one (L. major_MRC-02) to be selected for GMP production. This study addresses a major roadblock in the development of vaccines for leishmaniasis, providing a key resource for CHIM studies of sand fly transmitted cutaneous leishmaniasis.

microbiology↗

bioRxiv2017

Copy number variants implicate cardiac function and development pathways in earthquake-induced stress cardiomyopathy

The pathophysiology of stress cardiomyopathy (SCM), also known as takotsubo syndrome, is poorly understood. SCM usually occurs sporadically, often in association with a stressful event, but clusters of cases are reported after major natural disasters. There is some evidence that this is a familial condition. We have examined three possible models for an underlying genetic predisposition to SCM. Our primary study cohort consists of 28 women who suffered SCM as a result of two devastating earthquakes that struck the city of Christchurch, New Zealand, in 2010 and 2011. To seek possible underlying genetic factors we carried out exome analysis, Cardio-MetaboChip genotyping array analysis and array comparative genomic hybridization on these subjects. The most striking finding from these analyses was the observation of a markedly elevated rate of rare, heterogeneous copy number variants (CNV) of uncertain clinical significance (in 12/28 subjects). Several of these CNVs clearly impacted on genes of cardiac relevance including RBFOX1, GPC5, KCNRG, CHODL, and GPBP1L1. There is no physical overlap between the CNVs, and the genes they impact do not fall into a clear pathophysiological pathway. However, the recognition that SCM cases display a high rate of unusual CNV, and that SCM predisposition may therefore be associated with these CNVs, offers a novel perspective and a new approach by which to understand this enigmatic condition.

genetics↗