Biology subjects

Kraemer, J.

Publications and source records attributed to Kraemer, J..

3 recordsLinked to original sources

bioRxiv2025

Transcriptomic assessment of the Black Judaicus scorpion (Hottentotta judaicus) toxin arsenal and its potential bioeconomic value

Scorpion venoms are likewise a medical burden as well as a source of novel bioresources. Despite their important dual role, the venoms of most scorpion species remain under- or unstudied. Among these is the venom of the Black Judaicus scorpion, Hottentotta judaicus (Simon, 1872), a common yet neglected species native to the Middle East. Here, we employ venom gland transcriptomics to investigate its toxin-encoding precursor profile to gain insight into its toxin repertoire. The venom was found to be composed primarily of various short scorpion toxins, long scorpion toxins from the 3 C-C as well as the 4 C-C type, and enzymatic components. Minor components include, defensins and putative antimicrobial peptides. Several identified toxins show similarity to known neurotoxins from lethal buthids or to toxins with translational value in biomedicine, agriculture, and industrial production, thus rendering H. judaicus both, a potential health concern and source of novel bioresources. Our work provides an extended perspective on the venom profile of this species and represents a basis for future follow-up studies.

zoology↗

bioRxiv2025

Venomous Maggots? A first exploration of the toxin arsenal of larval stages of the horse fly Tabanus autumnalis

As a rapidly evolving trait, animal venom exhibits compositional variation even at the intraspecific level between populations, ontogenetic stages and sexes. In extreme cases venom is used for different functional purposes across ontogenetic stages. This phenomenon occurs for example in case of horse flies (Tabanidae), which utilize venom for predation during the larval stage and for blood feeding in the adult stage. While the venom composition and activity of adult tabanids has been investigated for some species, nothing is known about the venom compounds of tabanid larvae. With the current study we provide first insights into the venom composition of larval stages of a tabanid. Besides a plethora of hydrolyzing enzymes, we find the venom of T. autumnalis larvae dominated by peptide toxins. Some of these peptide toxins could be annotated as putative neurotoxins and cytolytic peptides and these compounds likely are the main drivers of fast prey incapacitation. Previous studies identified the main functional constituents utilized by tabanid imagines for blood feeding to be protease inhibitors affecting vasoconstriction and thrombin to promote blood feeding. Interestingly we find highly similar putative protease inhibitors in the larval venom, though with relatively low expression levels. This provides a first indication for a shifted expression profile between the venom of tabanid life stages to fulfill both the predatory needs of the larvae and the blood lust of female imagines.

molecular biology↗

bioRxiv2021

Does an artistic representation of brand logos increase their effect on customers?

BackgroundIn numerous fMRI studies, brands strongly confound the customers economic decisions on a neural level by modulating cortical activity in reward-related areas. ObjectiveTo test the hypothesis that the effect of logos can be increased by artistic logo representations, we presented logos in original and artistically changed versions during fMRI. MethodsFollowing a pre-study survey on the familiarity of original brand logos, 15 logos rated as "familiar" and 10 logos rated as "unfamiliar" were selected for fMRI experiment. During fMRI, 15 healthy subjects were presented with original and artistically changed logos out of the familiar/unfamiliar categories. A whole-brain and ROI analysis for reward-related areas were performed. Moreover, logo-induced valence and arousal were measured with the self-assessment manikin. ResultsWhole-brain analysis revealed activation in bilateral visual cortex for artistically changed logos (familiar/unfamiliar) compared to original logos. No significant effect could be detected for the ROI analysis. On average, the logos caused neutral emotions. However, when analyzing valence and arousal for familiar/unfamiliar and original/artistically changed logos separately, familiar original logos evoked stronger positive emotions than familiar artistically changed logos. Artistically changed logos (familiar/unfamiliar) excited participants significantly more than original logos. ConclusionArtistically changed logos elicit activation in the bilateral visual cortex but not in reward-related areas.

neuroscience↗