RUI: Salamander Greenrod/blue Cone Visual Pigment Gene Characterization

Citadel Military College Of South Carolina, Charleston SC

Investigators

Abstract

Rod and cone cells contain closely related but distinct photoreceptor proteins called opsins, which have diverged to meet the differing requirements of night and day vision. A recent study describes the first evidence for an exception to that rule. The tiger salamander SWS II, P432, a cone-like pigment, is expressed in both the blue sensitive cones and green rods. The promoter for the tiger salamander SWS II gene has been cloned and shown to be functionally active in photoreceptor cells. One goal of this research is to identify and characterize the unique regulatory elements in the SWS II promoter. An additional goal is to clone and sequence the SWS II, P434 opsin promoter from the closely related frog, Xenopus. By comparing the salamander and Xenopus promoters, as well as other promoters that drive rod or cone specific expression, the study will contribute to the understanding of how the cell type specific expression is achieved at the molecular level. The data will test the hypothesis that the promoter of the tiger salamander SWS II, P432 opsin gene contains both rod and cone-specific elements, driving opsin gene expression in both rods and cones. This research will provide the basis for an undergraduate molecular genetics course, for undergraduate genetics labs as well as undergraduate independent research projects. Undergraduate biology majors and pre-service science teachers in these courses will gain exposure to science as a process by participating in classroom laboratory exercises designed around this research. Independent research students will be encouraged to present their data at local and national meetings. These opportunities are critical in the development of students as scientists and science educators.