Dong Hyun Shin

The maternal transcription factor Dorsal (Dl) functions as bothan activator and a repressor in a context-dependent manner tocontrol dorsal-ventral patterning in the Drosophila embryo. Previous studies have suggested that Dl is an intrinsic activatorand its repressive activity requires additional corepressors thatbind corepressor-binding sites near Dl-binding sites. However,the molecular identities of the corepressors have yet to beidentified. Here, we present evidence that Capicua (Cic) isinvolv

The sog, a fly homologue of the vertebrate chordin, is expressed in the presumptive neurogenic ectoderm and also the ventral midline during Drosophila embryogenesis. Previously, two enhancers, called the primary and shadow enhancer, respectively, were found to direct sog expression in the neurogenic ectoderm. However, efforts to identify an enhancer that directs sog expression in the ventral midline have failed. Here, we present evidence that the sog shadow enhancer has dual activities to direct

The short gastrulation (sog) shadow enhancer directs early and late sog expression in the neurogenic ectoderm and the ventral midline of the developing Drosophila embryo, respectively. Here, evidence is presented that the sog primary enhancer also has both activities, with the late enhancer activity dependent on the early activity. Computational analyses showed that the sog primary enhancer contains five Dorsal (Dl)-, four Zelda (Zld)-, three Bicoid (Bcd)-, and no Single-minded (Sim)-binding sit

The shadow enhancer of the short gastrulation (sog) gene directs its sequential expression in the neurogenic ectoderm and the ventral midline of the developing Drosophila embryo. Here, we characterize three unusual features of the shadow enhancer midline activity. First, the minimal regions for the two different enhancer activities exhibit high overlap within the shadow enhancer, meaning that one developmental enhancer possesses dual enhancer activities. Second, the midline enhancer activity rel