Changes in Na+-K+, ATPase Expression and Activity in the Blue Crab Callinectes sapidus in Response to an Increase in Environmental Salinity

         Jansen Weaver,  Biology             

Faculty Mentor: Dr. Donald Lovett

              The purpose of the study is to determine how the enzyme Na+, K+-ATPase in blue crabs is affected when the crabs are acclimated to very low salinities and then transferred to high salinities.  This enzyme is crucial to osmoregulation because it actively pumps salt from the surrounding seawater into the crab’s blood.  In this summer project blue crabs were tended daily because they must be acclimated to the low salinity for at least three weeks before they could be used for the study.  Changes in gene expression and activity of the Na+, K+-ATPase enzyme in response to changes in salinity to try to explain how Na+, K+-ATPase is regulated in the crab.   In order to study these changes, gill tissue was extracted and homogenized from the crab after acclimation to high salinity and at different times after there was a transfer to low salinity.  RNA was extracted from the gill tissues and was investigated by using reverse transcriptase and amplification of cDNA using primers specific for the gene coding of Na+, K+-ATPase.  The enzymatic activity of Na+, K+-ATPase was measured via a spectrophotometer.  It was also necessary to measure the osmotic concentration of both the water the crabs were living in and the crab blood.  This is an ongoing project that still does not have definitive results.  I hope to continue working on this project during the academic year.

Personal Statement

              The Summer Undergraduate Research Program was a very positive experience for me.  I learned so much about different lab procedures, which I would have never been exposed to in a classroom lab.  The “hands-on” science really helped me understand the correlations between the knowledge that I gained in the classroom and the procedures performed in the lab.  The real benefit of this program however were the relationships made between our science majors and with this institution’s science faculty.  I have become very close with several professors which will only enrich the rest of my time here at The College of New Jersey.  I strongly believe that this experience helped mold my undergraduate science education in a way that will allow me to best choose my eventual career path.  This type of exposure is unusual for a sophomore or junior in college, and that is what makes this program such a phenomenal opportunity.