The RET proto-oncogene is expressed in the developing kidney and enteric nervous system during vertebrate embryogenesis. It has two major splicing variants; RET9 and RET51. The expression pattern of the two variants appears to vary among the developing organisms. RET9 plays a major role in development of kidney and excretory system whereas the role of RET 51 seems to be of maintenance of these systems after development. The protein RET is a transmembrane receptor which expresses itself in the cell surface and initiates the signal transduction pathways for cellular differentiation and proliferation of the cell. The different expression patterns shown by RET 9 and RET51 isoforms and the work of other researchers indicating that different RET splice variants result in different phenotype when expressed independently, are demonstrations of the importance of these splice variations in RET functioning. In order to expand our understanding on the mechanism of RET splicing, the 3\u27 end of the RET 9 isoform was isolated and a new construct was created that contained the exons and introns involved in the RET9 and RET51 splice variations. This region was placed into a mammalian expression vector in both orientations and the ability to measure changes in splicing with these constructs was measured. As a sequential step, in this study two different constructs of a specific region of RET were designed and analyzed using RTPCR and Q-PCR to demonstrate the mechanism of splicing. These constructs are planned to be further used as a model for the study of conditions that lead to splicing of Human RET proto-oncogene. While no differences were seen in initial studies, the development of the constructs and the evaluation of these constructs will provide an opportunity to study this important splicing event in more detail
