Title: Visualization of Calcium Channel Subunits in Schistosoma mansoni
Authors: Melissa Sanchez1, Pauline M. Cupit1, and Charles Cunningham1
Affiliations: 1Center for Evolutionary and Theoretical Immunology, University of New Mexico
Abstract: The human parasite Schistosoma mansoni is one of the most significant causative agents of schistosomiasis which affects about 207 million people worldwide. The only widely available treatment for this disease is praziquantel due to its availability and cost effectiveness. While this drug has been used for more than 30 years its mechanism of action remains unknown though voltage gated Ca2+ channel β subunits have been suggested to play an important role. The purpose of our study is to determine the site and strength of expression of two such β subunits - the CaC (conventional) and CaV (variable) β subunits. While the gene expressing the conventional subunit is found throughout metazoans, that expressing CaV β is found only in the Platyhelminthes to which Schistosoma spp belong. Here we describe the use of in-situ (ISH) and fluorescent in-situ (FISH) hybridization to visualize and quantify the expression of both Caβ subunits. Cryosectioning was used to obtain longitudinal sections of male S. mansoni. Sense and antisense probes for ISH were digoxigenin-labeled and visualized with BCIP. FISH probes were custom designed and consisted of multiple, singly labeled fluorescent oligonucleotides. The results of ISH identified similar expression of the proteins. FISH is being developed to quantify the level of expression of both genes. This study will provide a better understanding of the distribution of CaC and CaV β subunits in Schistosoma mansoni.