Metabolites from marine invertebrates and their symbiotic microorganisms: molecular diversity discovery, mining, and application

Metabolites from marine organisms have proven to be a rich source for the discovery of multiple potent bioactive moleculeswith diverse structures. In recent years, we initiated a program to investigate the diversity of the secondary metabolites frommarine invertebrates and their symbiotic microorganisms collected from the South China Sea. In this review, representativecases are summarized focusing on molecular diversity, mining, and application of natural products from these marineorganisms. To provide a comprehensive introduction to the field of marine natural products, we highlight typical moleculesincluding their structures, chemical synthesis, bioactivities and mechanisms, structure-activity relationships as well as biogenesis. The mining of marine-derived microorganisms to produce novel secondary metabolites is also discussed through theOSMAC strategy and via partial chemical epigenetic modification. A broad prospectus has revealed a plethora of bioactivenatural products with novel structures from marine organisms, especially from soft corals, gorgonians, sponges, and theirsymbiotic fungi and bacteria.

Seagull Lake,Western Eyre Peninsula,South Australia:A Saline Lake to Benefit from Climate Change? Ⅰ. Geomorphology,Invertebrates,Birds and the Future

Seagull Lake is an unusual saline lake,having a marine spring connected to a large continental ecosystem.With climate change the balance between the two is likely to change.This lake originated about 6000 years ago as a

What is the difference between marine and limnetic-terrestrial associations of nematodes with invertebrates?

Zoo-and phyto-parasitic nematodes of the order Rhabditida and zooparasites of the subclass Dorylaimia are well known,due largely to their medical,veterinarian and agricultural significance.However,there have been many switches from a free-living to a symbiotic(including parasitism)mode of existence in the evolutionary trajectories of various nematode clades.Here,we attempt to summarize all known cases of symbioses(from commensalism to true parasitism)between marine nematodes representing nonparasitic taxa and various larger animals,ranging from protists to vertebrates.Most cases are of nematodes relating to dwelling on crustaceans(ectocommensalism)or living in the body cavity and internal organs of various invertebrates(endoparasitism or parasitoidism).Ectocommensal species may differ from their free-living relatives in their longer filiform bodies and enlarged ventral and caudal glands,which may be interpreted as adaptations for the purpose of fixation on the body surface of a motile host.Endoparasitic species are characterized by deep anatomical modification,including rudimentation of the alimentary tract and hypertrophy of reproductive organs.Unlike terrestrial and limnetic invertebrates,marine invertebrates have almost no intestinal nematode dwellers.The evolutionary trajectories of nematode dwellers of marine and nonmarine invertebrates are compared.

Proteomic analysis of F_(1)hybrids and intermediate variants in a Littorina saxatilis hybrid zone

Proteomic analysis was carried out on the Crab(upper-shore)and Wave(lower-shore)ecotypes of Littorina saxatilis from a hybrid zone at Silleiro Cape,Spain.Proteome profiles of individual snails were obtained.Protein expression in F_(1)hybrid snails bred in the laboratory and snails with intermediate shell phenotypes collected from the mid-shore were compared with Crab and Wave ecotypes using analytical approaches used to study dominance.Multivariate analysis over many protein spots showed that the F_(1)snails are distinct from both ecotypes but closer to the Wave ecotype.The intermediate snails are highly variable,some closer to the Crab and others to the Wave ecotype.Considered on a protein by protein basis,some proteins are significantly closer in expression to the Crab and others to the Wave ecotype for both F_(1)and intermediate snails.Furthermore,a significant majority of proteins were closer in expression to the Wave ecotype for the F_(1),consistent with the multivariate analysis.No such significant majority toward either the Crab or Wave ecotype was observed for the intermediate snails.The closer similarity of F_(1)and Wave ecotype expression patterns could be the result of similar selective pressures in the similar mid-shore and low-shore environments.For a significantly larger number of proteins,intermediate snails were closer in expression to the ecotype having the lower expression,for both Crab and Wave ecotypes.This is somewhat unexpected as lower expression might be expected to be an indication of impairment of function and lower fitness.Proteomic analysis could be important for the identification of candidate proteins useful for gaining improved understanding of adaptation and barriers to gene flow in hybrid zones.