Across the animal kingdom, Hox genes are organized in clusters whose genomic organization reflects their central roles in patterning along the anterior/posterior (A/P) axis . While a cluster of Hox genes was present in the bilaterian common ancestor, the origins of this system remain unclear (cf. ). With new data for two representatives of the closest extant phylum to the Bilateria, the sea ane...

Actinia equina, the beadlet sea anemone, is a very labile species, displaying variable colour patterns, broad habitat choice and diverse modes of reproduction. Historically, studies using genetic markers such as allozymes and differences in habitat choice lead several authors to propose that different colour morphs could represent different species. One of the species defined was A. fragacea. I...

A highly specific cellular recognition system, capable of distinguishing between syngeneic and allogeneic tissue, exists in Anthopleura elegantissima, a sea anemone that lives in clonal colonies and attacks foreign clones. During the attack, specialized surface protrusions (acrorhagi) are used for stinging. The recognition process was studied by presenting various tissues to the surface of infl...

Transdermal delivery is an attractive option for drug delivery. Nevertheless, the skin is a tough barrier and only a limited number of drugs can be delivered through it. The most difficult to deliver are hydrophilic drugs. The stinging mechanism of the cnidarians is a sophisticated injection system consisting of microcapsular nematocysts, which utilize built-in high osmotic pressures to inject ...

The use of membrane active toxins as toxic moieties in the construction of immunotoxins (ITs) is an attractive alternative to overcome some of the problems of classical ITs since these new conjugates are based in the use of a different mechanism of killing undesired cells. Pore-forming cytolysins from sea anemones were used in the construction of ITs targeted to different cell types including t...

A high resolution structure in solution has been determined for the polypeptide neurotoxin I, from the sea anemone Stichodactyla helianthus, using NMR data, distance geometry calculations, and refinement by back-calculation of two-dimensional nuclear Overhauser enhancement (NOE) spectra. A set of 913 distance constraints derived from NOEs was used, together with a large set of lower distance bo...

An attempt has been made to identify electrical correlates of behaviour in Metridium senile (L.), a sea-anemone whose neuromuscular physiology and structure are already familiar (Parker, 1919; Hall &Pantin, 1937; Batham &Pantin, 1950a,b,c; 1951; 1954; Pantin, 1952, 19656; Batham, Pantin & Robson, i960; Robson, 1961; Ross, 19600,6). In a recent paper Josephson (1966) described electrical potenti...

C R E D IT : A D A M R E IT Z E L Genome sequencers have just jumped down to a lower branch on the tree of life, and the view has given them a new perspective on animal evolution. The newly decoded DNA of a few-centimeter-tall sea anemone looks surprisingly similar to our own, a team led by Nicholas Putnam and Daniel Rokhsar from the U.S. Department of Energy Joint Genome Institute in Walnut Cr...

The spontaneous activity and responses to electric stimulation of actinians have been intensively studied (e.g. Pantin, 1935a, b, c, d; Ross, 1952, 1957a, b; Horridge, 1958) for the light which they might throw on the functioning of the 'elementary nervous system', i.e. a nervous network lacking the physical concentration of neurones found in ganglia and brains. It seems desirable to add to thi...

-1. Amino acid, keto acid and imino acid substrate specificities of octopine dehydrogenase (ODH) from seven marine invertebrate sources were investigated. 2. Three groups of ODH enzymes were identified determined, largely, by their use of L-lysine as an alternative amino acid substrate, 3. The broadly specific ODH from the sea anemone, Calliactes parasitica, utilized L-arginine and L-lysine at ...