Dr. Silva has spent many summers as a visiting scientist at the MDI Biological Laboratory. In the past few years, he has been working to identify all the elements that are involved in the regulation of cellular pH in the rectal gland of the dogfish shark. The goals of Dr. Silva’s work this summer is to complete the characterization of elements involved in the disposal of CO2 by the rectal gland cells, carbonic anhydrase, SLC4 and NEH transporters, using standard molecular biology techniques.