Biology subjects

Mbaye, A.

Publications and source records attributed to Mbaye, A..

4 recordsLinked to original sources

bioRxiv2026

Walking on the Moon: Hypogravity drives the emergence of a proprioception-dependent locomotor state

Animals must adapt locomotion to changing environmental conditions, but how the nervous system flexibly controls movement remains unclear. Gravity provides a powerful perturbation because it alters body loading, limb dynamics, and proprioceptive feedback. Apollo astronauts often skipped on the Moon, adopting an asymmetric gait rarely used on Earth, yet the sensorimotor basis of this behaviour is unknown. Here, by studying hypogravity locomotion in humans and mice, we show that reduced gravity reveals a conserved proprioception-dependent mechanism for locomotor state expression. In humans, skipping in simulated lunar gravity is generated through flexible temporal reconfiguration of existing motor modules rather than construction of a new motor architecture. In mice, simulated lunar gravity elicited a skipping-like locomotor state, and genetic elimination of muscle proprioceptors abolished this response. Thus, hypogravity reveals how proprioceptive feedback enables flexible expression of locomotor states.

neuroscience↗

bioRxiv2025

Wnt signaling modulates tissue mechanics, actin order, and regeneration in Hydra vulgaris

Hydra vulgaris is a powerful model organism in the study of axial patterning and regeneration. While recent models emphasize the importance of mechanical cues in establishing the body axis of Hydra tissue spheres, the precise role of the Wnt pathway, known to be central to axial patterning, in regulating tissue mechanics and cytoskeletal organization remains unclear. In this paper, we pharmacologically modulated the canonical Wnt pathway using Alsterpaullone and iCRT14 and assessed their effects on regeneration, tissue rheology, osmotic oscillations and actin organization in Hydra tissue spheres. We found that Wnt activation prevents full regeneration, softens the constitutive tissues, disrupts osmotic oscillations, leads to an accumulation of dense actin filaments but impairs their orientational order. Conversely, we found that Wnt inhibition partially impairs regeneration and reduces actin filament presence while preserving alignment. These results support the underlying hypotheses of two existing mechano-chemical models of Hydra patterning, suggesting that Wnt-driven feedbacks on both tissue stiffness and actin order could contribute to the robust emergence of body axes. Our findings highlight the possibility of redundant and coupled mechanisms in the Hydra patterning system, potentially explaining its robustness.

biophysics↗

bioRxiv2025

An orally available PfPKG inhibitor blocks sporozoite infection of the liver

Malaria remains a global health threat exacerbated by emerging resistance to antimalarial therapies and insecticides, climate-driven outbreaks, and limited chemoprotective options. Here, we report the characterization of RUPB-61, the first orally bioavailable inhibitor of Plasmodium falciparum cGMP-dependent protein kinase (PfPKG). RUPB-61 prevents infection by P. falciparum and P. cynomolgi sporozoites, including the formation of hypnozoites by the latter. A single oral dose blocks liver infection by P. berghei sporozoites in vivo, demonstrating efficacy consistent with further development as a once-weekly prophylaxis based on pharmacokinetic modeling. The compound retains activity against field isolates resistant to chloroquine, mefloquine, cycloguanil, sulfadoxine and pyrimethamine, suggesting low likelihood of cross-resistance to existing antimalarials. Structural studies and free energy-based modeling guided-compound design prospectively validated the predictive accuracy of an in silico model of PfPKG interactions with this chemotype. While selectivity profiling identified off-target activity against human kinases, structural modeling provides a clear path for optimization. These results establish PfPKG inhibitors as promising candidates for chemoprevention and support further preclinical development of the RUPB-61 chemotype. Author SummaryMalaria remains a serious global health threat, made worse by growing resistance to existing drugs and the spread of insecticide-resistant mosquitoes. A critical gap in our prevention toolkit is the lack of safe, long-acting oral drugs that stop malaria parasites from infecting the liver - the first and obligatory step of every new infection. Here, we report the characterization of RUPB-61, a compound that blocks an enzyme that the malaria parasite needs to invade and survive in the liver. We show that a single oral dose completely prevents liver infection in mice, and that the compound remains active against parasites that are resistant to several currently used antimalarial drugs. Using X-ray crystallography and computer-based modeling, we determined how RUPB-61 binds to its target in atomic detail, providing a roadmap for designing improved versions. While the compound shows some unwanted interactions with human proteins, our structural data offer clear strategies to solve this challenge. Together, these findings provide a solid foundation for developing a new class of once-weekly oral malaria prevention drugs.

microbiology↗

bioRxiv2021

Profile of the in silico secretome of the palm dieback pathogen, a fungus that puts natural oases at risk

Understanding biotic changes that occur alongside climate change constitute a research priority of global significance. Here, we address a plant pathogen that poses a serious threat to life on natural oases, where climate change is already taking a toll and severely impacting human subsistence. Fusarium oxysporum f. sp. albedinis is a pathogen that causes dieback disease on date palms, a tree that provides several critical ecosystem services in natural oases; and consequently, of major importance in this vulnerable habitat. Here, we assess the current state of global pathogen spread, we annotate the genome of a sequenced pathogen strain isolated from the native range and we analyse its in silico secretome. The palm dieback pathogen secretes a large arsenal of effector candidates including a variety of toxins, a distinguished profile of secreted in xylem proteins (SIX) as well as an expanded protein family with an N-terminal conserved motif [SG]PC[KR]P that could be involved in interactions with host membranes. Using agrobiodiversity as a strategy to decrease pathogen infectivity, while providing short term resilient solutions, seems to be widely overcome by the pathogen. Hence, the urgent need for future mechanistic research on the palm dieback disease and a better understanding of pathogen genetic diversity.

plant biology↗