(353a) An in Vivo and in silico Approach to Study Antisense Transcription: A Short Cut to Higher Order System Response

Antisense interactions are present in all domains of life. Typically sense-antisense RNA pairs originate from overlapping genes with convergent face to face promoters, and are speculated to be involved in gene regulation. Recent studies indicate the role of transcriptional interference in regulating expression of genes in convergent orientation. We present a modeling and experimental framework to understand convergent transcription that combines the effects of transcriptional interference and cis-antisense RNA based regulation. Our model shows that combining transcriptional interference and antisense RNA interaction adds multiple-levels of regulation which affords a highly tunable biological output, ranging from first order response to complex higher-order response. To study this system we have created a library of experimental constructs with engineered transcriptional interference and antisense interaction by using face-to-face inducible promoters separated by carefully tailored DNA sequences to control expression of a set of fluorescent reporter proteins. Studying these coupled gene expression mechanisms allows for an understanding of higher order behavior of gene expression networks and design of novel synthetic genetic devices.