Project description:During tetrapod limb development, the HOXA13 and HOXD13 transcription factors are critical for the emergence and organization of the autopods, the most distal aspect where digits will develop. Since previous work had suggested that the Dbx2 gene is a target of these factors, we set up to analyze in detail this potential regulatory interaction. We used a chromatin conformation capture approach (4Cseq) to characterize the regulatory domain and interactions of the transcription factor Dbx2 and of its neighboring genes Nell2 and Ano6 in distal and/ or proximal forelimbs of E12 mouse embryos. In particular, we analyzed their interaction with distal limb specific regulatory elements (DLE1 and DLE2) by the analysis of H2K27ac coverages (Beccari et al 2016) and Hoxa13/Hoxd13 binding (Sheth R et al 2016). We report that Dbx2, Nell2 and Ano6 are expressed in distal limb buds and are controlled by the same enhancers located close to Dbx2. As the Nell2 and Ano6 genes are localized into two different topologically associating domains (TADs) flanking the Dbx2 locus, we conclude that these enhancers can overcome TAD boundaries in either direction, to co-regulate a set of genes located in distinct chromatin domains.
Project description:During tetrapod limb development, the HOXA13 and HOXD13 transcription factors are critical for the emergence and organization of the autopods, the most distal aspect where digits will develop. Since previous work had suggested that the Dbx2 gene is a target of these factors, we set up to analyze in detail this potential regulatory interaction. We used a chromatin conformation capture approach (4Cseq) to characterize the regulatory domain and interactions of the transcription factor Dbx2 and of its neighboring genes Nell2 and Ano6 in distal and/ or proximal forelimbs of E12 mouse embryos. In particular, we analyzed their interaction with distal limb specific regulatory elements (DLE1 and DLE2) by the analysis of H2K27ac coverages (Beccari et al 2016) and Hoxa13/Hoxd13 binding (Sheth R et al 2016). We report that Dbx2, Nell2 and Ano6 are expressed in distal limb buds and are controlled by the same enhancers located close to Dbx2. As the Nell2 and Ano6 genes are localized into two different topologically associating domains (TADs) flanking the Dbx2 locus, we conclude that these enhancers can overcome TAD boundaries in either direction, to co-regulate a set of genes located in distinct chromatin domains.
Project description:During tetrapod limb development, the HOXA13 and HOXD13 transcription factors are critical for the emergence and organization of the autopods, the most distal aspect where digits will develop. Since previous work had suggested that the Dbx2 gene is a target of these factors, we set up to analyze in detail this potential regulatory interaction. We used a chromatin conformation capture approach (4Cseq) to characterize the regulatory domain and interactions of the transcription factor Dbx2 and of its neighboring genes Nell2 and Ano6 in distal and/ or proximal forelimbs of E12 mouse embryos. In particular, we analyzed their interaction with distal limb specific regulatory elements (DLE1 and DLE2) by the analysis of H2K27ac coverages (Beccari et al 2016) and Hoxa13/Hoxd13 binding (Sheth R et al 2016). We report that Dbx2, Nell2 and Ano6 are expressed in distal limb buds and are controlled by the same enhancers located close to Dbx2. As the Nell2 and Ano6 genes are localized into two different topologically associating domains (TADs) flanking the Dbx2 locus, we conclude that these enhancers can overcome TAD boundaries in either direction, to co-regulate a set of genes located in distinct chromatin domains.
Project description:Enhancer-promoter interactions preferentially occur within boundary-insulated topologically associating domains (TADs), limiting inter-TAD interactions. Enhancer clusters in linear proximity, termed super-enhancers (SEs), ensure high target gene expression levels. Little is known about SE topological regulatory impact during craniofacial development. Here, we identified 2232 genome-wide putative SEs in mouse cranial neural crest cells (CNCCs), 147 of which target genes establishing CNCC positional identity during face formation. In second pharyngeal arch (PA2) CNCCs, a multiple SE-containing region, partitioned into Hoxa Inter-TAD Regulatory Element 1 and 2 (HIRE1 and HIRE2), establishes long-range inter-TAD interactions selectively with Hoxa2, that is required for external and middle ear structures. HIRE2 deletion in a Hoxa2 haploinsufficient background results in microtia. HIRE1 deletion phenocopies the full homeotic Hoxa2 knockout phenotype and induces PA3 and PA4 CNCC abnormalities correlating with Hoxa2 and Hoxa3 transcriptional downregulation. Thus, SEs can overcome TAD insulation and regulate anterior Hoxa gene collinear expression in a CNCC subpopulation-specific manner during craniofacial development.
Project description:Enhancer-promoter interactions preferentially occur within boundary-insulated topologically associating domains (TADs), limiting inter-TAD interactions. Enhancer clusters in linear proximity, termed super-enhancers (SEs), ensure high target gene expression levels. Little is known about SE topological regulatory impact during craniofacial development. Here, we identified 2232 genome-wide putative SEs in mouse cranial neural crest cells (CNCCs), 147 of which target genes establishing CNCC positional identity during face formation. In second pharyngeal arch (PA2) CNCCs, a multiple SE-containing region, partitioned into Hoxa Inter-TAD Regulatory Element 1 and 2 (HIRE1 and HIRE2), establishes long-range inter-TAD interactions selectively with Hoxa2, that is required for external and middle ear structures. HIRE2 deletion in a Hoxa2 haploinsufficient background results in microtia. HIRE1 deletion phenocopies the full homeotic Hoxa2 knockout phenotype and induces PA3 and PA4 CNCC abnormalities correlating with Hoxa2 and Hoxa3 transcriptional downregulation. Thus, SEs can overcome TAD insulation and regulate anterior Hoxa gene collinear expression in a CNCC subpopulation-specific manner during craniofacial development.
Project description:Enhancer-promoter interactions preferentially occur within boundary-insulated topologically associating domains (TADs), limiting inter-TAD interactions. Enhancer clusters in linear proximity, termed super-enhancers (SEs), ensure high target gene expression levels. Little is known about SE topological regulatory impact during craniofacial development. Here, we identified 2232 genome-wide putative SEs in mouse cranial neural crest cells (CNCCs), 147 of which target genes establishing CNCC positional identity during face formation. In second pharyngeal arch (PA2) CNCCs, a multiple SE-containing region, partitioned into Hoxa Inter-TAD Regulatory Element 1 and 2 (HIRE1 and HIRE2), establishes long-range inter-TAD interactions selectively with Hoxa2, that is required for external and middle ear structures. HIRE2 deletion in a Hoxa2 haploinsufficient background results in microtia. HIRE1 deletion phenocopies the full homeotic Hoxa2 knockout phenotype and induces PA3 and PA4 CNCC abnormalities correlating with Hoxa2 and Hoxa3 transcriptional downregulation. Thus, SEs can overcome TAD insulation and regulate anterior Hoxa gene collinear expression in a CNCC subpopulation-specific manner during craniofacial development.
Project description:Enhancer-promoter interactions preferentially occur within boundary-insulated topologically associating domains (TADs), limiting inter-TAD interactions. Enhancer clusters in linear proximity, termed super-enhancers (SEs), ensure high target gene expression levels. Little is known about SE topological regulatory impact during craniofacial development. Here, we identified 2232 genome-wide putative SEs in mouse cranial neural crest cells (CNCCs), 147 of which target genes establishing CNCC positional identity during face formation. In second pharyngeal arch (PA2) CNCCs, a multiple SE-containing region, partitioned into Hoxa Inter-TAD Regulatory Element 1 and 2 (HIRE1 and HIRE2), establishes long-range inter-TAD interactions selectively with Hoxa2, that is required for external and middle ear structures. HIRE2 deletion in a Hoxa2 haploinsufficient background results in microtia. HIRE1 deletion phenocopies the full homeotic Hoxa2 knockout phenotype and induces PA3 and PA4 CNCC abnormalities correlating with Hoxa2 and Hoxa3 transcriptional downregulation. Thus, SEs can overcome TAD insulation and regulate anterior Hoxa gene collinear expression in a CNCC subpopulation-specific manner during craniofacial development.
Project description:Enhancer-promoter interactions preferentially occur within boundary-insulated topologically associating domains (TADs), limiting inter-TAD interactions. Enhancer clusters in linear proximity, termed super-enhancers (SEs), ensure high target gene expression levels. Little is known about SE topological regulatory impact during craniofacial development. Here, we identified 2232 genome-wide putative SEs in mouse cranial neural crest cells (CNCCs), 147 of which target genes establishing CNCC positional identity during face formation. In second pharyngeal arch (PA2) CNCCs, a multiple SE-containing region, partitioned into Hoxa Inter-TAD Regulatory Element 1 and 2 (HIRE1 and HIRE2), establishes long-range inter-TAD interactions selectively with Hoxa2, that is required for external and middle ear structures. HIRE2 deletion in a Hoxa2 haploinsufficient background results in microtia. HIRE1 deletion phenocopies the full homeotic Hoxa2 knockout phenotype and induces PA3 and PA4 CNCC abnormalities correlating with Hoxa2 and Hoxa3 transcriptional downregulation. Thus, SEs can overcome TAD insulation and regulate anterior Hoxa gene collinear expression in a CNCC subpopulation-specific manner during craniofacial development.