Starfish

The next step in increasing oyster culture intensity might involve hatchery production and settling of spat on cultch. Once again, the cultch would be later distributed over a bed leased or owned by the oyster culturist (Eig. 1). Control of predators such as starfish and oyster drills could easily be a part of culture at all levels. 

Most recendy the stmcture of pyrrolosine has been shown to be an isomeric C-nucleoside analogue of 9-dea2ainosine, which is 7-(P-D-ribofuranosyl)-4-oxo-3Ff,5E -pyrrolo[3-2-i/ pyrimidine (29). Pyrrolosine inhibits development of starfish embryos. 

Two other pyrrolopyrimidine nucleoside antibiotics, mycalisines A and B (56,57), have been isolated from the sponge Mycale sp. (173). These bioactive marine metaboHtes inhibit cell division of starfish eggs. 

Marine corals secrete organohalogen compounds that act as a feeding deterrent to Starfish. 

Coelenterates and Echinoderms. Coelenterate and echinoderm toxins range from small molecular weight amines, to sterols, to large complex carbohydrate chains, to proteins of over 100,000 daltons. Molecular size sometimes reflects taxonomy, e.g., sea anemones (Actiniaria) all possess toxic polypeptides varying in size from 3,000 to 10,000 daltons while jellyfish contain toxic proteins (ca. 100,000 daltons). Carotenoids have been isolated from Asterias species (starfish), Echinoidea (sea urchins), and Anthozoans such as Actiniaria (sea anemones) and the corals. These are sometimes complexed with sterols (J5). 

Goad (40) and others have extensively reviewed coelenterate and echinoderm sterols including the saponins found in starfish and sea cucumbers. Cholesterol is a common sterol in most families, except for gorgonians and zoanthids some soft corals contain polyhydroxylated sterols. The amount of variation associated with phylogeny is illustrate in the echinoderms by the fact that crinoids, ophuiroids, and echinoids contain A 5 sterols while holothuriodeans and asteroids contain A 7 sterols. Some classes contain uniquely structured sterols. 

There has been considerable discussion regarding the mode of action of the sea cucumber and starfish saponins. Both the triterpene and steroidal glycosides inhibit both Na/K ATPase and Ca/Mg ATPase 06) possibly as a result of their aglycone structures. However, their detergent properties cause membrane disruption which will influence the activity of membrane-bound enzymes such as the ATPases. In investigating the actions of saponins on multilamellar liposomes, it was found that cholesterol serves as the binding site for such saponins and that cholesterol-free lip-somes are not lysed by saponins 107). 

Many of the toxins obtained from coelenterates and echinoderms, because of their hemolytic or cytotoxic actions, are assumed to have a general disruptive action on cell membranes. However, since many of these toxins are capable of forming pores or channels in the plasma membrane of cells, their cytolytic actions may be a result of this highly selective action. On the other hand, the saponins from starfish and sea cucumbers have a direct lytic action as a result of their detergent action on the integrity of cells. 

Labbe, J-C., Capony, J-P., Caput, D., Cavadore, J-C., Derancourt, J., Kaghad, M., Lelias, J-M., Picard, A., and Doree, M. (1989a). MPF from starfish oocytes at first meiotic metaphase is a heterodimer containing one molecule of cdc2 and one molecule of cyclin B. EMBO J. 8 3053-3058. 

Labbe, J. C., Picard, A. Peaucellier, G., Cavadore, J. C., Nurse, P., and Doree, M. (1989b). Purification of MPF from starfish identification as the HI histone kinase p34cpossible mechanism for its periodic activation. Cell 57 253-263. 

Nurse Work in starfish suggested that Cdk activity remained quite high, so that is the simplest model, and that is likely to be the case in fission yeast as well. We are cataloguing all the different components to see if we can work out the regulation of Cdk. It is consistent with but not yet proven that cdk regulation could regulate S phase between meiosis I and meiosis II. But I am worried about this mouse observation. Did you look at total HI histone kinase ... 

Korotchenko and coworkers detected PG-like compounds in five starfish from the Sea of Japan Asterias amurensis, Distolasterias nippon, Evasterias r. tabulata, Lysastrosoma anthosticta, and Patina pectinifera [189]. Perry and Epel showed that Pisaster ochraceous homogenates were able to oxidize AA [190]. Early studies on oocyte maturation in starfish suggested that HETE s might play a role [195]. Two compounds, 12- and 15-HETE, were able to induce oocyte maturation. Subsequent work showed that the activity was actually due to 8-HETE (33), which was a minor contaminant of both HETE preparations [196]. The 8R enantiomer of this compound (33) and 8R-HEPE (32) were also isolated from the aqueous extracts of Patiria miniata from the Gulf of California [197],... 

The absolute stereochemistries for both compounds were determined by CD analysis of the p-bromobenzoate derivatives. Two other eicosanoids were also isolated from whole animals [198], The trihydroxylated oxylipin 8jR,11S,12R-trihydroxyeicosa-5Z,9 ,14Z,17Z-tetraenoic acid (trioxilin A4,150) was detected in, or isolated from, five starfish species P. miniata, Dermasterias imbricata, Pycnopodia helianthoides, Culcita novaeguinea, and Nardoa tubercolata. Its structure was determined by H and 13C NMR and FAB-MS analyses of the natural product and of an acetonide derivative. The co6 analog of this compound (151) was isolated only from P. helianthoides. The relative stereochemistry in these metabolites (150, 151) was established from a comparison of NMR shifts with malyngic acid, a trihydroxylated C18 compound isolated from Lyngbya majuscula, while the absolute stereochemistry was proposed on the basis of the earlier isolation of 8R-HETE from P. miniata. 

Fig. 17. The STARFISH dodecamer of Kitov et al. with the Pk trisaccharide linked laterally at 2 and showing subnanomolar inhibitory activity against Shiga-like toxin I.23... 

Fig. 18. A variant of the STARFISH 10-mer in which the Pk antigen is linked to the central glucose core at the anomeric position.166...

Similarly to the STARFISH design already described (Fig. 17), the peripheral and radial presentation of five Pk-trisaccharide residues presenting tailored spacers could... 

The presence of Li+ results in the reversible inhibition of the hormone-induced meiotic maturation of starfish oocytes [226], and also reverses the inhibitory effect of forskolin on the spontaneous resumption of meiosis in uncoated mouse oocytes in vitro [227]. In the latter case, the effect of Li+ upon the adenylate cyclase response occurs only after it has been activated by forskolin. 

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