TY - JOUR T1 - An embryonic system to assess Wnt transcriptional targets JF - bioRxiv DO - 10.1101/129056 SP - 129056 AU - Jahnavi Suresh AU - Nathan Harmston AU - Ka Keat Lim AU - Prameet Kaur AU - Helen Jingshu Jin AU - Jay B. Lusk AU - Enrico Petretto AU - Nicholas S. Tolwinski Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/04/21/129056.abstract N2 - During animal development, complex signals determine and organize a vast number of tissues using a very small number of signal transduction pathways. These developmental signaling pathways determine cell fates through a coordinated transcriptional response that remains poorly understood. The Wnt pathway is involved in a variety of these cellular functions, and its signals are transmitted in part through a β-catenin/TCF transcriptional complex. Here we report an in vivo Drosophila assay that can be used to distinguish between activation, de-repression and repression of transcriptional responses, separating upstream and downstream pathway activation and canonical/non-canonical Wnt signals in embryos. We find specific sets of genes downstream of both β-catenin and TCF with an additional group of genes regulated by Wnt, while the non-canonical Wnt4 regulates a separate cohort of genes. We correlate transcriptional changes with phenotypic outcomes of cell differentiation and embryo size, showing our model can be used to characterize developmental signaling compartmentalization in vivo. ER -