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  • 1
    Electronic Resource
    Electronic Resource
    Chemical aspects of mass spawning in corals. I. Sperm-attractant molecules in the eggs of the scleractinian coral Montipora digitata (1994)
    Springer
    Marine biology 118 (1994), S. 177-182 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This paper provides the first evidence for sperm chemotaxis in the Scleractinia. Montipora digitata Dana, 1845 (Scleractinia: Coelenterata) is a hermaphroditic coral which reproduces bi-annually, releasing egg-sperm bundles during the mass spawning at Magnetic Island (19°10′S; 146°52′E) in late spring-early summer, and autumn each year. The buoyant egg-sperm bundles float to the surface where they break apart, releasing eggs and sperm into the ocean. Fertilisation occurs after ∼30 min. Unfertilized eggs were collected, washed free of sperm, and freeze-dried. The eggs were extracted with dichloromethane, fractionated by chromatography on silica gel, and the fractions assayed for their ability to attract M. digitata sperm. The active fraction was further fractionated by high-performance liquid chromatography, resulting in the isolation of three highly unsaturated fatty alcohols: (1) dodeca-2,4-diynol; (2) tetradec-13-ene-2,4-diynol; (3) (14Z)-heptadeca-14,16-diene-2,4-diynol. Of these three compounds, only Compound 1 attracted sperm of M. digitata. Synthetic Compound 1, produced from simple precursors by known reactions, possessed sperm-attracting activity comparable to the naturally derived attractant. Preliminary experiments suggest that the natural mixture of Compounds 1, 2 and 3 in the ratio 1:4:9 is more effective in attracting sperm from M. digitata than sperm from other Montipora species. Sperm attractants may act to reduce the incidence of hybridisation between different species of Montipora.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00349783
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  • 2
    Electronic Resource
    Electronic Resource
    Chemical aspects of mass spawning in corals. II. (-)-Epi-thunbergol, the sperm attractant in the eggs of the soft coral Lobophytum crassum (Cnidaria: Octocorallia) (1995)
    Springer
    Marine biology 123 (1995), S. 137-143 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The eggs of Lobophytum crassum Von Marenzeller, 1886, collected at Magnetic Island (19°10′S; 146°52′E) in October or November between 1983 and 1993, contained significant amounts (6% dry weight) of (-)-epi-thunbergol, in addition to other terpenoid metabolites also present in the parent colony. (-)-Epi-thunbergol was not present in the tissues of the releasing colony. Using fluorocarbon droplets impregnated with the chemotactic molecules and a videomicroscopic technique for the direct observation of sperm under the influence of attractant molecules, we showed that (-)-epi-thunbergol, whether isolated from L. crassum or from a gorgonian octocoral (Briareum sp.), significantly attracts sperm from L. crassum colonies. Attraction could be detected using direct observation at concentrations as low as 3.25 μg ml-1. This is the first evidence for sperm chemotaxis in the Alcyonacea. Eggs from L compactum, a common alcyonacean coral at Orpheus Island (18°36′S; 146°29′E) contained (-)-thunbergol as the egg-specific compound. L. compactum was not found at Magnetic Island. (-)-Thunbergol from L. compactum and (+)-thunbergol from a Douglas fir tree both showed levels of attraction similar to (-)-epi-thunbergol against L. crassum sperm. Although L. crassum sperm were apparently neither stereo- nor enantio-specific in their selectivity for chemotactic molecules, (-)-epi-thunbergol was identified as the natural sperm attractant in the eggs of L. crassum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00350332
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  • 3
    Electronic Resource
    Electronic Resource
    A simple current direction meter and its applicability to marine ecological studies
    Amsterdam : Elsevier
    Journal of Experimental Marine Biology and Ecology 174 (1993), S. 115-119 
    Details
    ISSN: 0022-0981
    Keywords: Current ; Direction ; Flow ; Meter ; Technical design
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0022-0981(93)90254-L
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  • 4
    Electronic Resource
    Electronic Resource
    Shedding new light on scleractinian coral recruitment
    Amsterdam : Elsevier
    Journal of Experimental Marine Biology and Ecology 180 (1994), S. 189-202 
    Details
    ISSN: 0022-0981
    Keywords: Coral recruitment ; Edge effect ; Light regime ; Phototaxis ; Sedimentation
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0022-0981(94)90066-3
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  • 5
    Electronic Resource
    Electronic Resource
    Increase in tumor GADD153 mRNA level following treatment correlates with response to paclitaxel (2000)
    Springer
    Cancer chemotherapy and pharmacology 45 (2000), S. 381-388 
    Details
    ISSN: 1432-0843
    Keywords: Key wordsGADD153 ; MDR1 ; Paclitaxel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: We investigated the relationship between the basal and treatment-induced change in the tumor expression of the drug resistance gene MDR1 and the cellular injury response gene GADD153, and clinical response to paclitaxel treatment. Methods: MDR1 and GADD153 mRNA levels were measured by reverse transcriptase polymerase chain reaction (RT-PCR) in tumor samples obtained by fine needle aspiration biopsy from 14 patients before and 24 h after paclitaxel infusion. Results: There was no difference between responders and non-responders with respect to either the basal MDR1 mRNA level or the change in MDR1 mRNA level at 24 h after treatment (P = 0.464). Likewise, there was no difference in basal GADD153 mRNA level between responders and non-responders. However, there was a significantly greater increase in GADD153 mRNA at 24 h in responders compared with non-responders (P = 0.005). An increase in GADD153 mRNA level of 1.5-fold or higher predicted response with a sensitivity of 86% and a specificity of 100%. Conclusions: An increase in GADD153 mRNA level reflects chemotherapy-induced damage sufficient to be manifest as a clinically detectable reduction in tumor volume. Measurement of the change in GADD153 mRNA level successfully identified patients destined to respond as early as 24 h post-treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002800051006
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  • 6
    Electronic Resource
    Electronic Resource
    Variability of terpene content in the soft coralSinularia flexibilis (Coelenterata: Octocorallia), and its ecological implications (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 2285-2296 
    Details
    ISSN: 1573-1561
    Keywords: Allelopathy ; diterpenes ; soft corals ; Sinularia flexibilis ; Coelenterata ; Octocorallia ; variability ; competition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Colonies of the soft coralSinularia flexibilis (Quoy & Gaimard) (Coelenterata, Octocorallia) were collected at Lizard Island (14°40′S and 145°28′E) Research Station. Extraction of the corals and quantitative chemical analysis for the three major diterpene components, flexibilide, dihydroflexibilide, and sinulariolide, afforded average ratios of 4∶3∶1 respectively. Colonies, sized on the basis of the sterile stalk circumference, were analyzed for possible correlations between size and chemical composition. The major metabolite, flexibilide, was inversely correlated with colony size, while sinulariolide concentration showed a direct correlation. The concentration of dihydroflexibilide was independent of colony size. Samples were further analyzed with respect to site of collection. Colonies were collected at three distinct reefal sites. One was characterized by large monospecific stands ofParites cylindrica, a second was a sandy bottom site with a mixed community of soft corals and occasional scleractinians, while the third site was a very diverse reef community with many species of scleractinian corals.Sinularia flexibilis was well represented at each site, and the concentration of flexibilide and sinulariolide varied significantly among sites. The concentration of flexibilide was significantly higher at the third, highly competitive site, while the concentration of sinulariolide was highest at thePorites-dominated site. Dihydroflexibilide levels were independent of site. It seems likely that concentrations of flexibilide, a highly cytotoxic molecule involved in interference competition, and sinulariolide, a known algicide probably responsible for colony maintenance, may be influenced by their environments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00979664
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