Biofactories Applied to Future Antivenom Production

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  Image Credit: By Ssiltane - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=52242648 Biofactories Applied to Future Antivenom Production Abstract Background: Accidents caused by the  Loxosceles laeta  spider constitute a health problem in South America. Envenomation can lead to severe systemic manifestations, eventually compromising the patient’s life. Most regional health authorities consider antivenom administration the basis of effective treatment in the most serious cases. The availability of spider venom is the primary bottleneck for antivenom production. Herein, we present a novel biotechnological approach, based on the expression of recombinant versions of the most relevant toxin in loxoscelism, sphingomyelinase D (SphD), in insect larvae ( Spodoptera frugiperda ).  Methods: We produced two versions of SphD: one conserving its biological activities (wtSphD) and a second alternative that was designed to be genetically detoxified (dSphD...

Eye-specific detection and a multi-eye integration model of biological motion perception

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Eye-specific detection and a multi-eye integration model of biological motion perception

    Abstract

The term biological motion refers to the peculiar kinematics of living organisms. Their interconnected joints move at a fixed distance from each other, a pattern that is common among all locomotive, rigid animals. Across the animal kingdom, many species have developed specialized circuitry to visually recognize biologically moving stimuli and discriminate them from other patterns. Recently, this skill has also been observed in the distributed visual system of jumping spiders. These eight-eyed animals use three of their eye pairs to perceive motion. Then, the gaze of the remaining pair is shifted towards the detected object for further inspection. When presented with a biologically moving stimulus and a random one, jumping spiders turn to face the latter, demonstrating discrimination. In the current paper, we systematically tested the ability of jumping spiders to discriminate biological from random displays using every single eye-pair, by blocking the others with paint. The animals were able to discriminate the stimuli only when the anterior-lateral eyes were unblocked, performing at chance level with the other pairs. Crucially, the spiders preferred the biological stimulus, not the random one. To explain this preference reversal we hypothesized a model, describing how the anterior-lateral eyes' specialization in detecting biological motion feeds into a multi-eye integration system, generating more complex behavior from the combination of the simple, single-eye responses. We propose that this in-built modularity may be a solution to the limited resources of these invertebrates' brains, constituting a novel approach to visual processing.


Massimo De Agrò, Daniela C. Rößler, Paul S. Shamble
bioRxiv 2023.09.24.559175; doi: https://doi.org/10.1101/2023.09.24.559175