Biology subjects

Campagna, S.

Publications and source records attributed to Campagna, S..

3 recordsLinked to original sources

bioRxiv2026

Food reward in Bottlenose Dolphins (Tursiops truncatus) and Belugas Whales (Delphinapterus leucas) reduces heart rate and increase heart rate variability.

1.BackgroundHeart rate (HR) and HR variability (HRV) reflect the autonomic modulation of cardiac activity and are key indicators of physiological state and stress in vertebrates. However, measuring these parameters in cetaceans has been historically challenging due to the difficulty of recording electrocardiograms (ECGs) underwater. MethodsWe developed an all-in-one ECG suction-cup to record HR during apnea, respiration and food rewards in bottlenose dolphins (Tursiops truncatus, N = 8) and belugas (Delphinapterus leucas, N = 2). Moreover, we obtain comparative measurements of ECG waveform and HR oscillation in one killer whale (Orcinus orca). ResultsSpecies-specific ECG patterns were observed, including biphasic T waves in all three species and bifid P waves unique to belugas. All three species exhibited oscillations in resting HR and pronounced bradycardia during short apnea ([~]1 min), reflecting respiratory-linked autonomic modulation. Moreover, HR oscillations persisted throughout apnea, possibly reflecting a mechanism to cyclically improve body oxygenation during diving. Short-term food deprivation had no significant effects on bottlenose dolphins and belugas HR, while subsequent feeding ad libitum reduced HR (by [~]20% in dolphins, [~]40% in belugas) and increased HRV, suggesting the activation of vagal modulation. ConclusionsThis study establishes baseline HR and HRV parameters during breathing, apnea and food reward in three cetacean species, highlighting autonomic modulation across different behaviors and conditions and validate a non-invasive tool for studying marine mammal physiology.

physiology↗

bioRxiv2021

Chemical ecology of a tripartite symbiosis

Microbial symbiotic interactions, mediated by small molecule signaling, drive physiological processes of higher order systems. Metabolic analytic technologies advancements provide new avenues to examine how chemical ecology, or conversion of existing biomass to new forms, changes over a symbiotic lifecycle. We examine such processes using the tripartite relationship between nematode host Steinernema carpocapsae, its obligate mutualist bacterium, Xenorhabdus nematophila, and the insects they infect together. We integrate trophic, metabolomics, and gene regulation analyses to understand insect biomass conversion to nematode or bacterium biomass. Trophic analysis established bacteria as the primary insect consumers, with nematodes at trophic position 4.37, indicating consumption of bacteria and likely other nematodes. Significant, discrete metabolic phases were distinguishable from each other, indicating the insect chemical environment changes reproducibly during bioconversion. Tricarboxylic acid cycle components and amino acids were significantly affected throughout infection. These findings contribute to an ongoing understanding of how symbiont associations shape chemical environments. TeaserEntomopathogenic nematodes act as an apex predator in some ecosystems through altering chemical environments of their prey.

microbiology↗

bioRxiv2019

Rumen Bacteria and Serum Metabolites Predictive of Feed Efficiency Phenotypes in Beef Cattle

The rumen microbiome is critical in ruminant nutrition and contributes to nutrient utilization and feed efficiency in cattle. Therefore, the objective of this study was to interrogate microbial and biochemical factors affecting divergences in feed efficiency in Angus steers using 16S amplicon sequencing and untargeted metabolomics. Average residual feed intake (RFI) was calculated, and steers were divided into low- and high-RFI groups. Features were ranked in relation to RFI through supervised machine learning on microbial and metabolite compositions. Residual feed intake was associated with several attributes of the rumen bacterial community. Low-RFI steers were associated with decreased bacterial - (P=0.03) and {beta}-diversity (P<0.001). Several serum metabolites were associated with RFI. Based on fold change (high/low RFI), low-RFI steers had greater abundances of pantothenate (P=0.02). Machine learning on RFI was predictive of both serum metabolomic signature and rumen bacterial composition (AUC [≥]0.7). Log-ratio proportions of the bacterial classes Flavobacteriia over Fusobacteriia were enriched in low-RFI steers (F=6.8, P=.01). Greater proportions of pantothenate-producing bacteria, such as Flavobacteriia, and/or reductions in Fusobacteriia may result in improved nutrient utilization in low-RFI steers. Pantothenate and Flavobacteriia may serve as potentially novel biomarkers to assess or predict feed efficiency in Angus steers.

microbiology↗