Effect of elevated temperature, sea water acidification, and phenanthrene on the expression of genes involved in the shell and pearl formation of economic pearl oyster (Pinctada radiata)

Our study aims to examine the effect of some stressors on the gene expression levels of shell matrix proteins in a pearl oyster. Oysters were exposed to the different combinations of the temperature, pH, and phenanthrene concentration is currently measured in the Persian Gulf and the predicted ocean warming and acidification for 28 days. The expression of all the studied genes was significantly downregulated. Time and temperature had the greatest effects on the decreases in n19 and n16 genes expression, respectively. Aspein and msi60 genes expression were highly influenced by pH. Pearlin was affected by double interaction temperature and phenanthrene. Moreover, a correlation was observed among the expression levels of studied genes. This study represents basic data on the relationship between mRNA transcription genes involved in the shell and pearl formation and climate changes in pollutant presence conditions and acclimatizing mechanism of the oyster to the future scenario as well.

A new bioindicator, shell of Trachycardium lacunosum, and sediment samples to monitors metals (Al, Zn, Fe, Mn, Ni, V, Co, Cr and Cu) in marine environment: The Persian Gulf as a case

BACKGROUND

The present work was designed to detect heavy metal contents of Al, Zn, Fe, Mn, Ni, V, Co, Cr and Cu in sediments and shells of the Trachycardium lacunosum collected in polluted and unpolluted areas along the Persian Gulf.

METHODS

The samples were taken from surface sediments (0-10 cm) and shells of Trachycardium lacunosum in two separated areas (polluted and unpolluted) in northern part of the Persian Gulf, Asaluyeh Bay, during summer 2013. The prepared samples were analyzed by inductively coupled plasma-optical emission spectrometry (ICP-OES).

RESULTS

Based on the results, all measured metals including Al, Zn, Fe, Mn, Ni, V, Co, Cr and Cu were meaningfully higher in the sediment samples of polluted area compared to unpolluted area and the order of metal concentrations in the sediment samples were Cr > Co > V > Ni > Zn > Cu > Fe > Al > Mn in polluted area. In the case of shell samples of Trachycardium lacunosum, polluted area contained significantly higher contents of Al, Zn, Fe, Mn, Ni, Co, Cr and Cu compared to unpolluted area and the order of metal concentrations in the shell samples were Fe > Zn > Al > Mn > Cu > Cr > Ni > Co in the polluted area.

CONCLUSION

It was concluded that shells of the Trachycardium lacunosum can be used as a suitable bioindicator for heavy metals in the aquatic environment. Results confirmed that due to the possible contaminations by oil and gas activities near the polluted area perennial monitoring and mitigation measures is extremely necessary.