Protamine-like proteins analyses as emerging biotechnique for cadmium impact assessment on male mollusk Mytilus galloprovincialis (Lamarck 1819)

Abstract

Here, we report the industrial pollution effects studies as it pertains to cadmium on the reproductive health of Mytilus galloprovincialis. Mussels were removed from the biofouling of Conatex pannel after one year of exposition in a polluted site close to a disposal metallurgical factory. In testis of mussels housed in the polluted site, was observed, respect to a reference control site, a high cadmium bioaccumulation by inductively coupled plasma-mass spectrometry, and a 10 fold increase metallothionein 20 kDa gene (mt20) expression levels, by qPCR. Furthermore, mussels transferred in laboratory tanks from the reference site and exposed to 1.5, 5 and 10 µM CdCl₂ revealed 1.7; 3.2 and 4.5 fold testis mt20 expression increase respectively and a positive correlation with cadmium bioaccumulation. To evaluate the potential detrimental risk of such alterations on spermatozoa we carried out electrophoretic analyses on their protamine-like proteins. Protamine-like proteins from the polluted biofouling resulted all in aggregated form and showed by EMSA, the same decreased DNA binding ability of protamine-like proteins obtained from mussels exposed in laboratory tank to CdCl₂. Our results contribute to the studies concerning cadmium induced testis alterations and highlight protamine-like proteins analyses as emerging biotechnique for cadmium impact assessment on Mytilus galloprovincialis for the sensibility of changes in vivo and in vitro of protamine-like proteins state and their DNA binding affinity.