Biology subjects

Velarde, A.

Publications and source records attributed to Velarde, A..

4 recordsLinked to original sources

bioRxiv2026

Nutritional Anthelmintics: Chicory Reconfigures the Equine Holobiont Across Microbial, Parasitic, and Host Scales

Anthelmintic resistance in cyathostomins is escalating worldwide, threatening equine health and highlighting the need for sustainable, ecology-based parasite control strategies. Chicory (Cichorium intybus, Puna II) has emerged as a promising antiparasitic forage, yet its broader effects on the equine holobiont, parasites, microbiota, and host physiology remain poorly understood. We conducted a 32-day longitudinal grazing trial in young horses to assess how chicory affects parasitological outcomes, gut microbial ecology, nemabiome composition, behaviour, and host physiological and immune responses. Twenty-six naturally infected Anglo-Arabian horses were monitored weekly, with 13 grazing a chicory-based sward and 13 grazing a permanent pasture. Clinical parameters, body weight, and serum biochemistry remained stable across treatments, indicating that chicory was well tolerated. Immune profiles showed limited variation, although IL-10 increased in chicory-fed horses, suggesting subtle immune modulation. Behavioural observations revealed no signs of discomfort and indicated slightly enhanced social interactions in the chicory group. Chicory grazing produced a marked reduction in cyathostomin egg excretion, accompanied by species-specific shifts in nemabiome composition. Several cyathostomin taxa, including Cylicocyclus ashworthi, C. leptostomus, and C. nassatus, declined in chicory-fed horses, whereas certain Cylicostephanus spp increased, indicating differential sensitivity rather than uniform suppression. Concomitantly, chicory induced profound ecological changes in the gut microbiota, including reduced alpha diversity, increased beta dispersion, and destabilised individual microbial trajectories. Several bacterial lineages, particularly Oscillospiraceae, Clostridiaceae, Lachnospiraceae, and Bacteroidales, were differentially enriched, reflecting a functional reorganisation of the intestinal ecosystem. Together, these findings demonstrate that chicory reduces parasite fitness, reshapes nemabiome composition, and alters gut microbial ecology while maintaining host physiological stability. Chicory thus emerges as a promising ecological tool for parasite control, capable of modulating the equine holobiont in ways that complement and potentially reduce reliance on conventional anthelmintic strategies. However, because its effects on gut microbial ecology remain uncertain, and may include shifts resembling dysbiosis, future studies are needed to monitor microbial dynamics more closely and clarify the long-term ecological consequences of chicory grazing. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=136 SRC="FIGDIR/small/737212v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@7b7367org.highwire.dtl.DTLVardef@d5914aorg.highwire.dtl.DTLVardef@135ad65org.highwire.dtl.DTLVardef@10b0322_HPS_FORMAT_FIGEXP M_FIG C_FIG

systems biology↗

bioRxiv2026

AI-Powered Acoustic Surveillance for Early Detection of Calf Respiratory Disease

Effective management of Bovine Respiratory Disease Complex (BRDC) requires timely, non-invasive diagnostic tools to protect calf health and welfare. Among early clinical signs, coughing stands out as both frequent and informative. To explore its potential for early BRDC detection, we deployed an artificial intelligence (AI)-driven acoustic monitoring system that recorded over 2,730 hours of audio during a 30-day period. Four experimental pens, each housing seven calves and stratified by infection status and antibiotic treatment, were equipped with a dedicated microphone to enable targeted acoustic surveillance. This configuration enabled pen-specific detection of cough events, which were subsequently classified using an AI HuBERT-based model trained on 1,045 labelled clips. The classifier achieved 92% accuracy. Temporal patterns in cough frequency aligned with infection dynamics, treatment responses, and circadian patterns. Notably, AI-detected coughs consistently preceded clinical scores by 1-2 days, confirming the systems sensitivity to early respiratory disorders. These findings support the use of acoustic surveillance as a valid, scalable, and autonomous tool for continuous monitoring and early warning of respiratory diseases in calves. ImplicationsThis study demonstrates that AI-powered acoustic monitoring enables real-time, non-invasive detection of coughs in calves for early warning of respiratory diseases, outperforming traditional veterinarian clinical scoring by 1-2 days. Its high accuracy and sensitivity to respiratory infection dynamics and treatment effects position it as a scalable tool for precision livestock farming.

zoology↗

bioRxiv2024

The HIV-1 Nuclear Export Complex Reveals the Role of RNA in Crm1 Cargo Recognition

Crm1 is a highly conserved nuclear exportin that transports >1000 human proteins including ribonucleoprotein (RNP) complexes. The interface between Crm1 and RNP cargos is unknown. The HIV regulatory protein, Rev, was one of the first identified cargos for Crm1 and contains a prototypic nuclear export sequence (NES). We present the cryo-electron microscopy structure of the HIV-1 nuclear export complex (Crm1/Ran-GTP and the Rev/RRE RNP). Rev binds at a previously unseen protein-protein binding site that stabilizes a unique Crm1 dimer and positions two NESs within the Crm1 dimer. The orientation of Rev binding positions the RRE within a charged pocket on the inside of the Crm1 toroid, mediating direct RNA-Ran-GTP contacts, highlighting the significant role of the RRE in the interaction. Structure based mutations, combined with cell-based assays, show that Crm1 has multiple distinct cargo recognition sites and explains how Crm1 can recognize a diverse range of protein and RNP cargos.

biochemistry↗

bioRxiv2022

A Split-GAL4 screen identifies novel sleep-promoting neurons in the Ventral Nerve Cord of Drosophila

As in the mammalian system, sleep in Drosophila is regulated by multiple brain regions. Among them, neurons projecting to the dorsal Fan-Shaped Body (dFB) have been intensively studied and the data suggest they play a critical role in sleep regulation. The 23E10-GAL4 driver is the most widely used tool to label and manipulate dFB neurons. Multiple studies have reported that activation of 23E10-GAL4 neurons promotes sleep. However, anatomical analyses revealed that 23E10-GAL4 labels 23-30 dFB neurons in the Drosophila brain and many non-dFB neurons in the brain and in the Ventral Nerve Cord (VNC), the fly equivalent of the spinal cord. To better understand the role of individual dFB neurons in sleep regulation, we undertook a Split-GAL4 screen to gain access to subsets of 23E10-GAL4 expressing cells. In this study, we report the discovery of two VNC cholinergic sleep-promoting neurons labeled by the 23E10-GAL4 driver.

neuroscience↗