The Toxicological Intersection between Allergen and Toxin: A Structural Comparison of the Cat Dander Allergenic Protein Fel d1 and the Slow Loris Brachial Gland Secretion Protein

Slow lorises are enigmatic animal that represent the only venomous primate lineage. Their defensive secretions have received little attention. In this study we determined the full length sequence of the protein secreted by their unique brachial glands. The full length sequences displayed homology to the main allergenic protein present in cat dander. We thus compared the molecular features of the slow loris brachial gland protein and the cat dander allergen protein, showing remarkable similarities between them. Thus we postulate that allergenic proteins play a role in the slow loris defensive arsenal. These results shed light on these neglected, novel animals.

Diplodomica I. Chemical Composition of Repugnatorial Secretions of Cuban Endemic Millipede gen. Rhinocricus sp.

The composition of the repugnatorial secretion of some populations of the Cuban endemic millipede Rhinocricus inhabiting in the western region of the Cuban archipelago has been developed. Several quinonoids metabolites were identified. From some individuals (males), collected in forest and karst regions, 850 μg of a deep brown-red secretion were obtained, and directly introduced into analytical instrumental (GC-MS and FTIR). The analysis of FTIR and GC-MS spectra shows that major components of secretions are substituted hydroquinones, 1,4-benzoquinones and aldehydes. The biological effects of these defensive secretions were evaluated on pathogenic microorganisms, showing interesting antimicrobial action. The ecological and evolutionary significance of chemical differentiation in millipedes populations require further study.

Adhesive defence mucus secretions in the red triangle slug (Triboniophorus graeffei) can incapacitate adult frogs

Gastropods are known to secrete mucus for a variety of purposes, including locomotion, reproduction, adhesion to surfaces, and lubrication. A less commonly known function of mucus secretion in this group involves its use as a defence against predation. Among the terrestrial slugs, mucus that serves this particular purpose has been studied for only a handful of species under laboratory conditions, where it is thought to be produced for self-fouling or to make individuals difficult to consume. However, the mechanisms of how these defensive secretions operate and their effectiveness in deterring predation in the natural world have not be described in much detail. In this study, we provide evidence of adhesive mucus secretions in the red triangle slug (Triboniophorus graeffei) as an adaptation against predation. Field observations of a large red-eyed green tree frog (Litoria chloris) trapped in the mucus secretions of a nearby T. graeffei revealed that this mucus serves to incapacitate predators rather than just simply as an overall deterrence. Mechanical stimulation of T. graeffei under laboratory conditions revealed that adhesive secretions were produced from discrete sections of the dorsal surface when disturbed, leading to the production of a highly sticky and elastic mucus that was unlike the thin and slippery mucus used during locomotion. The adhesiveness of the defensive secretions was strengthened and reactivated when in contact with water. This appears to not only be the first description of defensive mucus production in this slug species but one of the first natural observations of the use of adhesive defence secretions to incapacitate a predator. The biomechanical properties of this mucus and its ability to maintain and strengthen its hold under wet conditions make it potentially useful in the development of new adhesive materials.