Metabolic fingerprinting as an indicator of biodiversity: towards understanding inter-specific relationships among Homoscleromorpha sponges

Abstract

Sponges are an important source of secondary metabolites showing a great diversity of structures and biological activities. Secondary metabolites can display specificity on different taxonomic levels, from species to phylum, which can make them good taxonomic biomarkers. However, the knowledge available on the metabolome of non-model organisms is often poor. In this study, we demonstrate that sponge chemical diversity may be useful for fundamental issues in systematics or evolutionary biology, by using metabolic fingerprints as indicators of metabolomic diversity in order to assess interspecific relationships. The sponge clade Homoscleromorpha is particularly challenging because its chemistry has been little studied and its phylogeny is still debated. Identification at species level is often troublesome, especially for the highly diversified Oscarella genus which lacks the fundamental characters of sponge taxonomy. An HPLC-DAD-ELSD-MS metabolic fingerprinting approach was developed and applied to 10 Mediterranean Homoscleromorpha species as a rapid assessment of their chemical diversity. A first validation of our approach was to measure intraspecific variability, which was found significantly lower than interspecific variability obtained between two Oscarella sister-species. Interspecific relationships among Homoscleromorpha species were then inferred from the alignment of their metabolic fingerprints. The resulting classification is congruent with phylogenetic trees obtained for a DNA marker (mitochondrial COI) and demonstrates the existence of two distinct groups within Homoscleromorpha. Metabolic fingerprinting proves a useful complementary tool in sponge systematics. Our case study calls for a revision of Homoscleromorpha with further phylogenetic studies and identification of additional chemical synapomorphic characters.

Lysophospholipids in the Mediterranean Sponge Oscarella tuberculata: Seasonal Variability and Putative Biological Role

“…The same approach was used to evaluate the O. tuberculata intraspecific variability in secondary metabolite production on a large geographic scale (along the Mediterranean coast). No significant variation in metabolite composition was found in different color morphotypes, with the intraspecific variability being essentially quantitative, marked by variation in the expression level of major compounds (Ivanišević et al, 2011). Spatial and temporal variations in concentrations of major secondary metabolites have been documented previously in a few sponges, ascidians, and other sessile marine invertebrates (Page et al, 2005;Lopez-Legentil et al, 2006;Abdo et al, 2007).…”

“…Oscarella tuberculata crude extract showed the highest bioactivity among Homoscleromorph species as detected by the standardized Microtox test. Another well-studied Homoscleromorph, Corticium candelabrum, which produces cytotoxic and antibacterial aminosterols (plakinamines), had a bioactivity about five times lower than O. tuberculata (Ivanišević et al, 2011). Oscarella tuberculata antitumoral and antimalarial activities also are comparable to that of C. candelabrum (unpublished data).…”

“…Oscarella tuberculata previously has been reported to produce unusual lipids such as rare and long alkyl chain 5-substituted pyrrole-2-carbaldehydes and sterol endoperoxides (Cimino et al, 1975;Aiello et al, 1991;Loukaci et al, 2004). However, our metabolic fingerprinting approach indicated a larger chemical diversity than previously reported (Ivanišević et al, 2011). The same approach was used to evaluate the O. tuberculata intraspecific variability in secondary metabolite production on a large geographic scale (along the Mediterranean coast).…”

“…After our work on the chemical diversity of Mediterranean Homoscleromorph sponges (Ivanišević et al, 2011), we focused attention on the species Oscarella tuberculata. In its environment, this thinly encrusting species has several colors (yellow to blue), has no known predator, and can cover in some places a high percentage (up to 100%) of the rocky substrate.…”

Irrigation and Light Access Effects on Coffea arabica L. Leaves by FTIR‑Chemometric Analysis

“…22 A more global metabolomics approach is called metabolic fingerprinting that can be used for purposes such as the quality control of medicinal plants as well as their characterization and classification. 23 Metabolic fingerprinting of an herbal sample is a characteristic profile of chromatographic or spectroscopic origin, which characterizes its composition. 24 Spectroscopy is an increasingly growing technique due to its rapidity, simplicity, and safety, as well as its ability to measure multiple attributes simultaneously without arduous sample preparation.…”