AaTs-1, a Tetrapeptide from Scorpion Venom Mitigates Demyelination and Neuroinflammation in a Cuprizone-Induced Model of Multiple Sclerosis

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  AaTs-1, a Tetrapeptide from Scorpion Venom Mitigates Demyelination and Neuroinflammation in a Cuprizone-Induced Model of Multiple Sclerosis Abstract Purpose This study focuses on the evaluation of the therapeutic potential of Tetrascorpin-1 (AaTs-1), a tetrapeptide isolated from Androctonus australis hector venom, proposed as a putative formyl peptide receptor 2 (FPR2) antagonist, in a cuprizone-induced murine model of Multiple sclerosis (MS), a chronic autoimmune and inflammatory disease of the central nervous system. Methods Acute demyelination was induced in mice by administering cuprizone (0.2% w/w in the diet) for six weeks. During the sixth week of cuprizone intake, demyelinated mice received intranasal administration of AaTs-1 at a dose of 50–100 µg/kg for five consecutive days, with 24-hour intervals between treatments. Results Behavioral assessments, immunological assays, and histological analyses revealed that AaTs-1 improved body weight, reduced behavioral impairments...

Nephila spider male aggregation: preference for optimal female size and web clustering

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Nephila spider male aggregation: preference for optimal female size and web clustering

Abstract

Sexual size dimorphism theory predicts biased operational sex ratios (OSRs) and an uneven distribution of males among certain females. We studied this phenomenon through a field census of the giant wood spider Nephila pilipes (family Nephilidae) in Singapore, a species where females are, on average, 6.9 times larger than males. Specifically, we tested two hypotheses concerning male distribution, given their tendency to aggregate in certain female webs. The optimal female size hypothesis predicts that males would predominantly occupy webs of intermediate-sized females. The web clustering hypothesis posits that more males would be found in webs closer together compared to those farther apart. Our snapshot census revealed a female-biased OSR (females: males = 1.85) with an uneven distribution of males in female webs. Most males were found in webs of intermediate-sized females aligning with the optimal female size hypothesis. Proximity among female webs was indicative of male presence, lending support to the web clustering hypothesis. While our study's limited sample size warrants caution, we conclude that in N. pilipes, male occupation of female webs is facilitated by the clustering of webs, and males prefer to cohabit with optimally sized, receptive females.

KUNTNER, M., KUNTNER, M., KUNTNER, E., KUNTNER, I., PUCER, J. F., ŠTRUMBELJ, E., & LI, D. Nephila spider male aggregation: Preference for optimal female size and web clustering. Integrative Zoology. https://doi.org/10.1111/1749-4877.12896