Project description:This SuperSeries is composed of the following subset Series: GSE23999: Mapping the binding regions of the cubitus interruptus (Ci) activator form GSE24024: Mapping the binding regions of the cubitus interruptus (Ci) repressor form GSE24028: Identification of genetic targets of Hh signaling in Drosophila Refer to individual Series
Project description:Alternative polyadenylation (APA) has been implicated in a variety of developmental and disease processes, such as stem cell differentiation and cancer. A particularly dramatic form of APA has been documented in the developing nervous system of flies and mammals, whereby a variety of neurogenic genes undergo coordinate extension of their 3’ UTRs. In Drosophila, the RNA-binding protein ELAV inhibits RNA processing at proximal polyadenylation (poly(A)) sites, thereby fostering the formation of 3’ extensions that can reach 12 kb in length. Here, we present evidence that paused Pol II plays an important role in the selective recruitment of ELAV to elongated genes. Replacing native promoters of elongated genes with heterologous promoters blocks normal 3’ extension in the nervous system, while native promoters can induce 3’ extension in ectopic tissues expressing ELAV. Computational analyses suggest that the promoter regions of elongated genes tend to contain paused Pol II and associated cis-regulatory elements such as GAGA. ELAV ChIP-Seq assays indicate pervasive binding to the promoter regions of extended genes. Our study provides the first evidence for a regulatory link between promoter-proximal pausing and APA. ELAV ChIP-Seq assays were conducted with nuclei obtained from 6-8 hr and 10-12 hr embryos
Project description:Alternative polyadenylation (APA) has been implicated in a variety of developmental and disease processes, such as stem cell differentiation and cancer. A particularly dramatic form of APA has been documented in the developing nervous system of flies and mammals, whereby a variety of neurogenic genes undergo coordinate extension of their 3’ UTRs. In Drosophila, the RNA-binding protein ELAV inhibits RNA processing at proximal polyadenylation (poly(A)) sites, thereby fostering the formation of 3’ extensions that can reach 12 kb in length. Here, we present evidence that paused Pol II plays an important role in the selective recruitment of ELAV to elongated genes. Replacing native promoters of elongated genes with heterologous promoters blocks normal 3’ extension in the nervous system, while native promoters can induce 3’ extension in ectopic tissues expressing ELAV. Computational analyses suggest that the promoter regions of elongated genes tend to contain paused Pol II and associated cis-regulatory elements such as GAGA. ELAV ChIP-Seq assays indicate pervasive binding to the promoter regions of extended genes. Our study provides the first evidence for a regulatory link between promoter-proximal pausing and APA.
Project description:Zelda binding in the early Drosophila melanogaster embryo marks regions subsequently activated at the maternal-to-zygotic transition
Project description:Despite being found in the notochord of several chordates, the roles of the Tbx2 subfamily of T-box transcription factors in the development of this tissue remain largely unknown. We explored the targets of the only Tbx2 subfamily member in Ciona intestinalis, Ci-Tbx2/3, by expressing mutant forms of the transcriptional regulator using the Ci-Bra promoter region. We produced a dominant interfering version of Ci-Tbx2/3 (Tbx2/3DBD) through expression of a truncated version consisting only of its DNA-binding domain (DBD) and a constitutive activator form by attaching the T-box of Ci-Tbx2/3 to the VP16 transactivation domain (Tbx2/3VP16). These constructs were introduced into 1-cell stage embryos and grown to the neurula (N) or mid-tailbud (mTb) stage to capture targets regulated throughout notochord morphogenesis. Ci-Tbx2/3 targets were ascertained using whole-genome custom Affymetrix microarrays to compare the transcription levels of Tbx2/3DBD and Tbx2/3VP16 expressing embryos to wild-type controls (Bra>GFP) at the neurula or mTb stages.
Project description:dFOXO targets in adult Drosophila melanogaster females, and the effect of insulin signalling and stress on binding. The experimets determined the binding locations of dFOXO in the whole adult female fly using ChIP-chip. The protocol was validated using mock conditions: pre-immune serum or IP on chromatin from foxo null flies. The response of this binding to stress induced by treatment of flies with paraquat or by their exposure to starvation, as well as the response to an insulin-signalling-reducing genetic manipulation (over-expression of dominant negative form of the insulin receptor), was determined.