The contamination of aquatic systems is a problem with worldwide concern. Among the responses observed in mollusks exposed to contaminants, shell alterations have been recently used as tool in toxicological studies. Changes in shell form and (micro)structure in mollusks sampled in contaminated sites in comparison to reference sites were reported in several species from different countries. However, the mechanisms associated to these alterations are still unknown. Studies have shown that the minor organic fraction of shell matrices (mostly composed of proteins, glycoproteins, proteoglycans, and polysaccharides) is responsible for controlling the biomineralization process. Therefore, changes in the composition or location of these biomolecules can affect shell structure and form. Considering that mollusk species belonging to different ecological niches can present distinct susceptibility to contaminants, the present proposal aims to use different techniques to characterize shell structures (e.g. SEM, EBSD), elemental composition (EDX) and the properties of the shell matrix, which will be investigated via FTIR, mono- and bi-dimensional gel electrophoresis, Western Blot, in vitro crystallization assay, proteomics and lectin profiling (ELLA). Three model mollusks will be investigated: Crassostrea brasiliana (filter-feeder), Lottia subrugosa (herbivore) and Stramonita brasiliensis (carnivore). They will be sampled in a known contamination gradient in Santos Estuarine System. Our analyses will allow the comparison of the results among sampling sites and among species and will indicate which species is more vulnerable to contaminants. In parallel, these results might elucidate the mechanism behind shell shape alterations.
News published in Agência FAPESP Newsletter about the scholarship: