Project description:The manuscript by D. Licastro and colleagues “Promiscuity of enhancer, coding and non-coding transcription functions in ultraconserved sequence elements” presents an overview of experimental and computational approaches employed by the authors to perform a multi-facet characterization of ultraconserved elements (UCEs). The authors present an interesting analysis where they investigate the transcription of UCEs in mouse development at different stages by conductin an microarray experiment. Some of these results are further verified by RT-PCR. 12 Samples, 4 groups 3 samples per group.
Project description:The manuscript by D. Licastro and colleagues “Promiscuity of enhancer, coding and non-coding transcription functions in ultraconserved sequence elements” presents an overview of experimental and computational approaches employed by the authors to perform a multi-facet characterization of ultraconserved elements (UCEs). The authors present an interesting analysis where they investigate the transcription of UCEs in mouse development at different stages by conductin an microarray experiment. Some of these results are further verified by RT-PCR.
Project description:Non-coding regulatory elements (NCRE) represent a major fraction of the human genome, play important roles in different biological pathways, and have the potential as genomic medicine targets. We developed a straightforward dual-CRISPR screening system capable of deleting thousands of NCREs genome-wide to study their functions in distinct biological contexts in K562 cells and 293T cells. We show that many NCREs, including ultraconserved elements (UCE), have silencer activity and play essential roles in cell growth and drug response. NCREs with redundant functions could also be identified from the screening data. This dual-CRISPR system is also compatible with single-cell sequencing. We identified that UCE PAX6_Tarzan might be critical in heart development, as removing it from human embryonic stem cells led to defects in cardiomyocyte differentiation. Our study provides further evidence that many NCREs have important biological functions contributing to human biology and diseases, and may serve as future drug targets.
Project description:Non-coding ultraconserved regions showing hundreds of consecutive bases of perfect evolutionary sequence conservation across mammalian genomes have intrigued biologists in the decade since they were first described. While many of these sequences are known to represent distant-acting enhancers, initial deletion studies in mice showed that their loss had no obvious impact on viability or fertility. To explore the discrepancy between extraordinary evolutionary constraint and an apparent lack of phenotypes when deleted in vivo, we used genome editing to create an expanded series of knockout mice lacking individual or combinations of ultraconserved brain enhancers near the essential neuronal transcription factor Arx. While the loss of any single or pair of ultraconserved enhancers resulted in viable and fertile mice, detailed phenotyping revealed neurological or growth abnormalities in nearly all cases, including substantial alterations of neuron populations and abnormalities of the dentate gyrus. Our results demonstrate the functional importance of ultraconserved enhancers and highlight that extreme sequence conservation may result from evolutionary selection against fitness deficits that appear subtle in a laboratory setting.
Project description:Translation of seed stored mRNAs is essential to trigger germination. However, when RNAPII re-engages RNA synthesis during the seed-to-seedling transition has remained in question. Combining csRNA-seq, ATAC-seq and smFISH in Arabidopsis thaliana we demonstrate that active transcription initiation is detectable during the entire germination process. Features of non-coding regulation such as dynamic changes in chromatin accessible regions, antisense transcription, as well as bidirectional non-coding promoters are widespread throughout the Arabidopsis genome. We show that sensitivity to exogenous ABSCISIC ACID (ABA) during germination depends on proximal promoter accessibility at ABA-responsive genes. Moreover, we provide genetic validation of the existence of divergent transcription in plants. Our results reveal that active enhancer elements are transcribed producing non-coding enhancer RNAs (eRNAs) as widely documented in metazoans. In sum, this study defining the extent and role of coding and non-coding transcription during key stages of germination expands our understanding of transcriptional mechanisms underlying plant developmental transitions.
Project description:Translation of seed stored mRNAs is essential to trigger germination. However, when RNAPII re-engages RNA synthesis during the seed-to-seedling transition has remained in question. Combining csRNA-seq, ATAC-seq and smFISH in Arabidopsis thaliana we demonstrate that active transcription initiation is detectable during the entire germination process. Features of non-coding regulation such as dynamic changes in chromatin accessible regions, antisense transcription, as well as bidirectional non-coding promoters are widespread throughout the Arabidopsis genome. We show that sensitivity to exogenous ABSCISIC ACID (ABA) during germination depends on proximal promoter accessibility at ABA-responsive genes. Moreover, we provide genetic validation of the existence of divergent transcription in plants. Our results reveal that active enhancer elements are transcribed producing non-coding enhancer RNAs (eRNAs) as widely documented in metazoans. In sum, this study defining the extent and role of coding and non-coding transcription during key stages of germination expands our understanding of transcriptional mechanisms underlying plant developmental transitions.
Project description:Translation of seed stored mRNAs is essential to trigger germination. However, when RNAPII re-engages RNA synthesis during the seed-to-seedling transition has remained in question. Combining csRNA-seq, ATAC-seq and smFISH in Arabidopsis thaliana we demonstrate that active transcription initiation is detectable during the entire germination process. Features of non-coding regulation such as dynamic changes in chromatin accessible regions, antisense transcription, as well as bidirectional non-coding promoters are widespread throughout the Arabidopsis genome. We show that sensitivity to exogenous ABSCISIC ACID (ABA) during germination depends on proximal promoter accessibility at ABA-responsive genes. Moreover, we provide genetic validation of the existence of divergent transcription in plants. Our results reveal that active enhancer elements are transcribed producing non-coding enhancer RNAs (eRNAs) as widely documented in metazoans. In sum, this study defining the extent and role of coding and non-coding transcription during key stages of germination expands our understanding of transcriptional mechanisms underlying plant developmental transitions.
Project description:Translation of seed stored mRNAs is essential to trigger germination. However, when RNAPII re-engages RNA synthesis during the seed-to-seedling transition has remained in question. Combining csRNA-seq, ATAC-seq and smFISH in Arabidopsis thaliana we demonstrate that active transcription initiation is detectable during the entire germination process. Features of non-coding regulation such as dynamic changes in chromatin accessible regions, antisense transcription, as well as bidirectional non-coding promoters are widespread throughout the Arabidopsis genome. We show that sensitivity to exogenous ABSCISIC ACID (ABA) during germination depends on proximal promoter accessibility at ABA-responsive genes. Moreover, we provide genetic validation of the existence of divergent transcription in plants. Our results reveal that active enhancer elements are transcribed producing non-coding enhancer RNAs (eRNAs) as widely documented in metazoans. In sum, this study defining the extent and role of coding and non-coding transcription during key stages of germination expands our understanding of transcriptional mechanisms underlying plant developmental transitions.
Project description:In this study, we have investigated the molecular interactions of an ultraconserved non-coding RNA, TUC338, which is highly upregulated in hepatocellular cancer and implicated in growth regulation. We have identified functional genomic and proteomic determinants of this lncRNA involved in modulation of gene expression.