BACKGROUND Abundant fossils from the Ediacaran and Cambrian showing cnidarian grade grossly suggest that cnidarian diversification occurred earlier than that of other eumetazoans. However, fossils of possible soft-bodied polyps are scanty and modern corals are dated back only to the Middle Triassic, although molecular phylogenetic results support the idea that anthozoans represent the first maj...

The circadian clock is a molecular network that translates predictable environmental signals, such as light levels, into organismal responses, including behavior and physiology. Regular oscillations of the molecular components of the clock enable individuals to anticipate regularly fluctuating environmental conditions. Cnidarians play important roles in benthic and pelagic marine environments a...

The symbiotic associations between cnidarians and dinoflagellate algae (Symbiodinium) support productive and diverse ecosystems in coral reefs. Many aspects of this association, including the mechanistic basis of host-symbiont recognition and metabolic interaction, remain poorly understood. The first completed genome sequence for a symbiotic anthozoan is now available (the coral Acropora digiti...

Stings of hymenoptera can induce IgE-mediated hypersensitivity reactions in venom-allergic patients, ranging from local up to severe systemic reactions and even fatal anaphylaxis. Allergic patients' quality of life can be mainly improved by altering their immune response to tolerate the venoms by injecting increasing venom doses over years. This venom-specific immunotherapy is highly effective ...

Phylogenetic analyses of toxin gene families have revolutionised our understanding of the origin and evolution of reptile venoms, leading to the current hypothesis that venom evolved once in squamate reptiles. However, because of a lack of homologous squamate non-toxin sequences, these conclusions rely on the implicit assumption that recruitments of protein families into venom are both rare and...

The cnidarian-dinoflagellate symbiosis is arguably one of the most important within the marine environment in that it is integral to the formation of coral reefs. However, the regulatory processes that perpetuate this symbiosis remain unresolved. It is essential to understand these processes, if we are to elucidate the mechanisms that support growth and resource accumulation by coral host, and ...

platelet aggregation inhibitory effect and anticoagulant properties of fractions separated from the venoms of cerastes persicus fieldi and echis carinatus were investigated. the partial fractionation was performed on a sephadex g-100 column. two fractions separated from cerastes persicus fieldi showed anti platelet aggregation activity on adp (200 µm)-induced platelet aggregation (ca 80% inhibi...

background : antivenom is still widely used in the treatment of envenomation as there are no vaccines or other effective agents available against animal venoms. recently, neurotoxins named birtoxin family have been described from parabuthus transvaalicus and androctonus crassicauda. the aim of the present study was to test the antibirtoxin antibodies for their ability to neutralize the lethal e...

Alloimmune specificity and histocompatibility, driven by genetic polymorphism, are ancient determinants of self-/non-self-recognition. Recent molecular genetic evidence has revealed an allodeterminant in the cnidarian Hydractinia that consistently predicts histocompatibility reactions.