CONTENT OF 70 kDa STRESS PROTEIN DURING ACCLIMATION OF MUSSEL MYTILUS EDULIS L. TO LOW SALINITY

Area of Science:

• Marine Biology
• Environmental Physiology
• Molecular Biology

Background:

• Bivalved mollusks like Mytilus edulis face environmental salinity fluctuations.
• Phenotypic adaptation involves physiological and molecular responses to environmental stress.
• Stress proteins, such as heat shock proteins (HSP70), play crucial roles in cellular protection and adaptation.

Purpose of the Study:

• To investigate the dynamics of stress-protein content in Mytilus edulis gill epithelium during adaptation to changing environmental salinity.
• To determine whether external salinity or internal medium osmolarity acts as the primary signal for stress-protein induction.

Main Methods:

• Mussels (Mytilus edulis) were subjected to low salinity conditions (10 ‰).
• Stress-protein content, specifically from the HSP70 family, was measured in gill epithelium.
• Mussels' extravisceral fluid osmolarity was measured in parallel with salinity changes.

Main Results:

• Stress proteins from the HSP70 family were induced by the 5th day of acclimation to low salinity.
• A strong correlation was observed between the induction of stress proteins and the osmolarity of the mussels' internal medium.
• External marine water salinity did not directly correlate with stress-protein induction.

Conclusions:

• The osmolarity of the internal medium is the key signal for stress-protein induction in Mytilus edulis.
• This finding highlights the importance of internal physiological regulation in response to environmental salinity changes.
• HSP70 family proteins are involved in the phenotypic adaptation of Mytilus edulis to hyposaline conditions.