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Gill Na+, K+-ATPase as a function of size and salinity in the blue crab, Callinectes sapidus Rathbun

UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
Tiandao Li (Creator)
Institution
The University of North Carolina Wilmington (UNCW )
Web Site: http://library.uncw.edu/

Abstract: Some kinetic properties of gill Na+,K+-ATPase of the blue crab, Callinectes sapidus, and its relation to osmotic regulation in juvenile and adult crabs were analyzed. Results suggest the presence of some differences in transport mechanisms for juvenile and adult blue crabs to maintain hemolymph concentration in dilute media. Adult and sub-adult crabs demonstrated fairly low levels of Na+,K+-ATPase activity in both anterior and posterior gills regardless of acclimation salinity. Juvenile blue crabs had much higher levels of Na+,K+-ATPase activity in both anterior and posterior gills relative to adults. Crabs acclimated to low salinity showed a significant increase in enzyme activity, both in anterior and posterior gills. The levels of enzyme activity in the anterior gills of juveniles showed a marked increase at low salinities. Enzyme activity in the posterior gills of juvenile crabs at 150 mOsm increased (35%) over sea water. However, there is a markedly higher specific activity increase (80%) in the anterior gills of smaller, juvenile crabs at this lower salinity. Sex had no effect on the enzyme activity relative to salinity. Abrupt transfer of juvenile and adult crabs from 1000mOsm to 150mOsm resulted in a gradual change in the Na+,K+-ATPase activity that reached steady-state levels within 7-10 days after the transfer. The time course for the increase in activity was preceded by an increase in the expression of the Na+,K+-ATPase a-subunit mRNA. The Na+,K+-ATPase of the posterior gills of both juvenile and sub-adult crabs showed an increased affinity for ATP at lower salinities, while that of the posterior gills of juvenile crabs had a higher affinity for Na+ than that of sub-adults at low salinity.

Additional Information

Publication
Thesis
A Thesis Submitted to the University of North Carolina Wilmington in Partial Fulfillment of the Requirements for the Degree of Master of Science
Language: English
Date: 2009
Keywords
Callinectes--Effect of potassium on, Callinectes--Effect of salt on
Subjects
Callinectes -- Effect of salt on
Callinectes -- Effect of potassium on