MEPS 224:149-156 (2001)  -  doi:10.3354/meps224149

ABSTRACT: Two-dimensional gel electrophoresis (2-DE) is a unique method of large-scale protein characterisation, and is a powerful approach in the study of protein expression. In the present work, the experimental conditions for 2-DE of foot proteins from the mussel Mytilus galloprovincialis Lmk were established; the technique was performed with intertidal and cultured mussels using Melanie 3 software for data analysis. This powerful technique enabled the visualisation of a total of 750 protein spots consistently expressed in the foot. The intensity of 92 selected spots was compared between intertidal and cultured mussels, and statistically significant differences were detected in the expression of 45 (48.9%) of the 92 proteins analysed. In 31 of these proteins, intensity was higher in the cultured stock than in the intertidal mussels, while in 14 proteins spot intensity was higher in the latter. Using mass spectrometry (MS) combined with sequence database searching, 6 of the most prominent differentially expressed proteins were analysed. Of these, 1 was identified as being Heat-shock Protein 70, and 2 were shown to be cytoskeleton-associated proteins, myosin and actin. Heat-shock Protein 70, which is known to be involved in cellular transport and chaperoning and associated with stress situations, was more highly expressed in intertidal mussels living in littoral areas than in cultured mussels. These findings are discussed in connection with the molecular changes involved in the adaptation of mussels to different ecological conditions.

KEY WORDS: Mytilus galloprovincialis · Two-dimensional gel electrophoresis · Proteome · Foot proteins