Biology subjects

Sar-Shalom, E.

Publications and source records attributed to Sar-Shalom, E..

4 recordsLinked to original sources

bioRxiv2025

YOLito: A generalizable model for automated mosquito detection

Understanding mosquito behavior is key to advancing research in ecology, evolution, and disease control, yet most behavioral assays rely on human-dependent methods, such as real-time observation or manual frame-by-frame annotation, limiting throughput and reproducibility. We present YOLito, a domain-generalized AI model for automated mosquito detection and behavioral quantification. Built on the Ultralytics YOLO framework and enhanced with Slicing-Aided Hyper Inference (SAHI), YOLito accurately detects multiple mosquitoes across diverse backgrounds and imaging conditions. Trained on a globally assembled dataset of 38,547 annotated images from 35 experimental setups across six laboratories and three public datasets, YOLito achieved high performance on unseen data (precision = 0.95; recall = 0.91) and generalized across mosquito species (Aedes, Anopheles, Culex) and assay types, including blood-feeding, sugar-feeding, and oviposition. By automating behavioral scoring, YOLito transforms traditional assays into scalable and reproducible experimental platforms. The accompanying open-source toolkit enables high-throughput extraction of metrics such as visit frequency, duration, and distance traveled, providing a standardized and extensible framework that bridges computer vision and vector biology.

animal behavior and cognition↗

bioRxiv2025

An OpIE2-DsRed marker disrupts female blood-feeding and shortens lifespan in the malaria vector Anopheles gambiae.

Anopheles gambiae is one of the principal vectors of human malaria. Over the past two decades, transgenic mosquito strains have been essential tools for studying mosquito biology and developing genetic control strategies such as gene drives. Mosquito transformants are typically identified using fluorescent markers, which are assumed to be phenotypically neutral. While generating CRISPR-based gene drive strains carrying an OpIE2-DsRed marker we unexpectedly found that transgenic females were unable to blood-feed and were consequently sterile, whereas males initially appeared normal and fertile. Given the potential utility of dominant, female-specific sterility for mosquito control, we established additional strains controlling for transgene content and integration site, confirming that the OpIE2-DsRed cassette caused the defect. Behavioral assays showed that females exhibited normal attraction to a membrane feeder but failed to initiate blood-feeding, performing repeated cycles of probing and proboscis grooming in rapid succession before ultimately leaving the feeder unfed. Microscopy showed that both sexes possessed a distally curved proboscis, providing a morphological explanation for the blood-feeding defect of females and the reduced male lifespan. A second promoter variant (OpIE2b), differing in flanking sequences at the IE-2 junction, drove strong marker expression without impairing blood-feeding or longevity. These findings demonstrate that minor differences in promoter architecture can produce major, unexpected phenotypic effects. OpIE2b provides a robust, phenotypically neutral marker for An. gambiae research, while OpIE2a highlights the need for rigorous validation of transgenic components intended for research and applied releases.

genetics↗

bioRxiv2025

Comparative chemosensory mechanisms underlying larval foraging and competitive advantage in Aedes albopictus and Aedes aegypti

The invasive Asian tiger mosquito, Aedes albopictus (Skuse), and yellow fever mosquito, Aedes aegypti (L.) are known to compete for resources during the larval stage, often resulting in the ecological displacement of Ae. aegypti by Ae. albopictus. The chemosensory system plays a pivotal role in larval foraging behavior and may contribute to the competitive advantage. Here, we employed comparative transcriptomics and functional characterization of odorant receptors (ORs) to investigate species-specific differences in larval olfaction. Notably, we uncovered functional variation within the conserved olfactory indole receptor clade, indicating distinct ecological adaptations across species and life stages. We also developed a novel approach to functionally characterize the larval sensory cone and mapped its receptor neuron projections to two key brain regions: the antennal lobe and the subesophageal ganglion. This study provides new insights into the molecular and neural basis of chemosensory-driven behavior in mosquito larvae and highlights the potential role of olfaction in shaping interspecies competition and ecological success.

neuroscience↗

bioRxiv2023

The evolution of borneol repellency in culicine mosquitoes

The use of essential oils derived from the camphor tree to repel mosquitoes is an ancient practice that originated in Southeast Asia and gradually spread to China and across Europe via the Maritime Silk Road. The olfactory mechanisms by which these oils elicit avoidance behavior are unclear. Here we show that plant bicyclic monoterpenoids and borneol specifically activate a neural pathway that originates in the orphan olfactory receptor neuron of the capitate peg sensillum in the maxillary palp, and projects to the mediodorsal glomerulus 3 in the antennal lobe. This neuron co-locates with two olfactory receptor neurons tuned to carbon dioxide and octenol that mediate human-host detection. We also confirm that borneol elicits repellency against human-seeking female mosquitoes. Understanding the functional role of the mosquito maxillary palp is essential to investigating olfactory signal integration and host-selection behavior.

evolutionary biology↗