scholarly journals Distinct core promoter codes drive transcription initiation at key developmental transitions in a marine chordate

2017 ◽  
Author(s):  
Gemma B. Danks ◽  
Pavla Navratilova ◽  
Boris Lenhard ◽  
Eric Thompson
Keyword(s):  
Transcription Initiation ◽  
Core Promoter ◽  
Ribosomal Protein Genes ◽  
Oikopleura Dioica ◽  
Transcription Start Sites ◽  
Spliced Leader ◽  
Genome Wide ◽  
A Genome ◽  
Cap Analysis ◽  
Male Specific

AbstractDevelopment is largely driven by transitions between transcriptional programs. The initiation of transcription at appropriate sites in the genome is a key component of this and yet few rules governing selection are known. Here, we used cap analysis of gene expression (CAGE) to generate bp-resolution maps of transcription start sites (TSSs) across the genome of Oikopleura dioica, a member of the closest living relatives to vertebrates. Our TSS maps revealed promoter features in common with vertebrates, as well as striking differences, and uncovered key roles for core promoter elements in the regulation of development. During spermatogenesis there is a genome-wide shift in mode of transcription initiation characterized by a novel core promoter element. This element was associated with > 70% of transcription in the testis, including the male-specific use of cryptic internal promoters within operons. In many cases this led to the exclusion of trans-splice sites, revealing a novel mechanism for regulating which mRNAs receive the spliced leader. During oogenesis the cell cycle regulator, E2F1, has been co-opted in regulating maternal transcription in endocycling nurse nuclei. In addition, maternal promoters lack the TATA-like element found in vertebrates and have broad, rather than sharp, architectures with ordered nucleosomes. Promoters of ribosomal protein genes lack the highly conserved TCT initiator. We also report an association between DNA methylation on transcribed gene bodies and the TATA-box, which indicates that this ancient promoter motif may play a role in selecting DNA for transcription-associated methylation in invertebrate genomes.

scholarly journals Discovery of widespread transcription initiation at microsatellites predictable by sequence-based deep neural network

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mathys Grapotte ◽  
Manu Saraswat ◽  
Chloé Bessière ◽  
Christophe Menichelli ◽  
Jordan A. Ramilowski ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Tandem Repeats ◽  
Specific Gene ◽  
Rna Seq ◽  
Transcription Start Sites ◽  
Long Read ◽  
Cap Analysis ◽  
Dna Tandem Repeats ◽  
Short Tandem ◽  
Str Polymorphism

AbstractUsing the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of transcription start sites (TSSs) in several species. Strikingly, ~72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probe these unassigned TSSs and show that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we develop Cap Trap RNA-seq, a technology which combines cap trapping and long read MinION sequencing. We train sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveil the importance of STR surrounding sequences not only to distinguish STR classes, but also to predict the level of transcription initiation. Importantly, genetic variants linked to human diseases are preferentially found at STRs with high transcription initiation level, supporting the biological and clinical relevance of transcription initiation at STRs. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism.

scholarly journals Prediction of the Sex-Associated Genomic Region in Tunas (Thunnus Fishes)

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yoji Nakamura ◽  
Kentaro Higuchi ◽  
Kazunori Kumon ◽  
Motoshige Yasuike ◽  
Toshinori Takashi ◽  
...  
Keyword(s):  
Sex Determination ◽  
Bluefin Tuna ◽  
Pacific Bluefin Tuna ◽  
Estrogen Sulfotransferase ◽  
Unique Region ◽  
Genome Wide ◽  
A Genome ◽  
Southern Bluefin Tuna ◽  
Male Specific ◽  
Female Genome

Fish species have a variety of sex determination systems. Tunas (genus Thunnus) have an XY genetic sex determination system. However, the Y chromosome or responsible locus has not yet been identified in males. In a previous study, a female genome of Pacific bluefin tuna (T. orientalis) was sequenced, and candidates for sex-associated DNA polymorphisms were identified by a genome-wide association study using resequencing data. In the present study, we sequenced a male genome of Pacific bluefin tuna by long-read and linked-read sequencing technologies and explored male-specific loci through a comparison with the female genome. As a result, we found a unique region carrying the male-specific haplotype, where a homolog of estrogen sulfotransferase gene was predicted to be encoded. The genome-wide mapping of previously resequenced data indicated that, among the functionally annotated genes, only this gene, named sult1st6y, was paternally inherited in the males of Pacific bluefin tuna. We reviewed the RNA-seq data of southern bluefin tuna (T. maccoyii) in the public database and found that sult1st6y of southern bluefin tuna was expressed in all male testes, but absent or suppressed in the female ovary. Since estrogen sulfotransferase is responsible for the inactivation of estrogens, it is reasonable to assume that the expression of sult1st6y in gonad cells may inhibit female development, thereby inducing the individuals to become males. Thus, our results raise a promising hypothesis that sult1st6y is the sex determination gene in Thunnus fishes or at least functions at a crucial point in the sex-differentiation cascade.

scholarly journals Discovery of widespread transcription initiation at microsatellites predictable by sequence-based deep neural network

2020 ◽  
Author(s):  
Mathys Grapotte ◽  
Manu Saraswat ◽  
Chloé Bessière ◽  
Christophe Menichelli ◽  
Jordan A. Ramilowski ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Tandem Repeats ◽  
Specific Gene ◽  
Rna Seq ◽  
Transcription Start Sites ◽  
Dna Motif ◽  
Long Reads ◽  
Cap Analysis ◽  
Dna Tandem Repeats ◽  
Short Tandem

Using the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of Transcription Start Sites (TSSs) in several species. Strikingly, ~ 72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probed these unassigned TSSs and showed that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we developed Cap Trap RNA-seq, a technology which combines cap trapping and long reads MinION sequencing. We trained sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveiled the importance of STR surrounding sequences not only to distinguish STR classes, as defined by the repeated DNA motif, one from each other, but also to predict their transcription. Excitingly, our models predicted that genetic variants linked to human diseases affect STR-associated transcription and correspond precisely to the key positions identified by our models to predict transcription. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism.

scholarly journals An optimized ChIP-Seq framework for profiling of histone modifications in Chromochloris zofingiensis

2021 ◽  
Author(s):  
Daniela Strenkert ◽  
Matthew Mingay ◽  
Stefan Schmollinger ◽  
Cindy Chen ◽  
Ronan C O'Malley ◽  
...  
Keyword(s):  
Fragment Size ◽  
Transcriptome Profiling ◽  
Formaldehyde Concentration ◽  
Structural Annotation ◽  
Transcription Start Sites ◽  
Genome Wide ◽  
Chip Experiment ◽  
A Genome ◽  
Dna Shearing ◽  
Chromochloris Zofingiensis

The eukaryotic green alga Chromochloris zofingiensis is a reference organism for studying carbon partitioning and a promising candidate for the production of biofuel precursors. Recent transcriptome profiling transformed our understanding of its biology and generally algal biology, but epigenetic regulation remains understudied and represents a fundamental gap in our understanding of algal gene expression. Chromatin Immunoprecipitation followed by deep sequencing (ChIP-Seq) is a powerful tool for the discovery of such mechanisms, by identifying genome-wide histone modification patterns and transcription factor-binding sites alike. Here, we established a ChIP-Seq framework for Chr. zofingiensis yielding over 20 million high quality reads per sample. The most critical steps in a ChIP experiment were optimized, including DNA shearing to obtain an average DNA fragment size of 250 bp and assessment of the recommended formaldehyde concentration for optimal DNA-protein crosslinking. We used this ChIP-Seq framework to generate a genome-wide map of the H3K4me3 distribution pattern and to integrate these data with matching RNA-Seq data. In line with observations from other organisms, H3K4me3 marks predominantly transcription start sites of genes. Our H3K4me3 ChIP-Seq data will pave the way for improved genome structural annotation in the emerging reference alga Chr. zofingiensis.

scholarly journals Live-cell single particle imaging reveals the role of RNA polymerase II in histone H2A.Z eviction

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Anand Ranjan ◽  
Vu Q Nguyen ◽  
Sheng Liu ◽  
Jan Wisniewski ◽  
Jee Min Kim ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Single Molecule ◽  
Transcription Initiation ◽  
General Mechanism ◽  
Pol Ii ◽  
Promoter Escape ◽  
Genome Wide ◽  
A Genome ◽  
Particle Imaging

The H2A.Z histone variant, a genome-wide hallmark of permissive chromatin, is enriched near transcription start sites in all eukaryotes. H2A.Z is deposited by the SWR1 chromatin remodeler and evicted by unclear mechanisms. We tracked H2A.Z in living yeast at single-molecule resolution, and found that H2A.Z eviction is dependent on RNA Polymerase II (Pol II) and the Kin28/Cdk7 kinase, which phosphorylates Serine 5 of heptapeptide repeats on the carboxy-terminal domain of the largest Pol II subunit Rpb1. These findings link H2A.Z eviction to transcription initiation, promoter escape and early elongation activities of Pol II. Because passage of Pol II through +1 nucleosomes genome-wide would obligate H2A.Z turnover, we propose that global transcription at yeast promoters is responsible for eviction of H2A.Z. Such usage of yeast Pol II suggests a general mechanism coupling eukaryotic transcription to erasure of the H2A.Z epigenetic signal.

scholarly journals Hda1C restricts the transcription initiation frequency to limit divergent non-coding RNA transcription

2021 ◽  
Author(s):  
Uthra Gowthaman ◽  
Maxim Ivanov ◽  
Isabel Schwarz ◽  
Heta P. Patel ◽  
Niels A. Müller ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Transcription Initiation ◽  
Histone Deacetylation ◽  
Gene Promoters ◽  
Genetic Screens ◽  
Fluorescence Measurements ◽  
Non Coding Rna ◽  
Genome Wide ◽  
A Genome ◽  
Initiation Frequency

ABSTRACTNucleosome-depleted regions (NDRs) at gene promoters support initiation of RNA Polymerase II transcription. Interestingly, transcription often initiates in both directions, resulting in an mRNA, and a divergent non-coding (DNC) transcript with an unclear purpose. Here, we characterized the genetic architecture and molecular mechanism of DNC transcription in budding yeast. We identified the Hda1 histone deacetylase complex (Hda1C) as a repressor of DNC in high-throughput reverse genetic screens based on quantitative single-cell fluorescence measurements. Nascent transcription profiling showed a genome-wide role of Hda1C in DNC repression. Live-cell imaging of transcription revealed that Hda1C reduced the frequency of DNC transcription. Hda1C contributed to decreased acetylation of histone H3 in DNC regions, supporting DNC repression by histone deacetylation. Our data support the interpretation that DNC results as a consequence of the NDR-based architecture of eukaryotic promoters, but that it is governed by locus-specific repression to maintain genome fidelity.

scholarly journals Trans-splicing of mRNAs links gene transcription to translational control regulated by mTOR

2018 ◽  
Author(s):  
Gemma Danks ◽  
Heloisa Galbiati ◽  
Martina Raasholm ◽  
Yamila N. Torres Cleuren ◽  
Eivind Valen ◽  
...  
Keyword(s):  
Gene Transcription ◽  
Growth Regulator ◽  
Translational Control ◽  
Oikopleura Dioica ◽  
Spliced Leader ◽  
Animal Density ◽  
Genome Wide ◽  
Trans Splicing ◽  
Initial Recovery ◽  
Favorable Conditions

AbstractIn phylogenetically diverse organisms, the 5’ ends of a subset of mRNAs are trans-spliced with a spliced leader (SL) RNA. The functions of SL trans-splicing, however, remain largely enigmatic. Here, we quantified translation genome-wide in the marine chordate, Oikopleura dioica, under inhibition of mTOR, a central growth regulator. Translation of trans-spliced TOP mRNAs was suppressed, showing that the SL sequence permits nutrient-dependent translational control of growth-related mRNAs. Under crowded, nutrient-limiting conditions, O. dioica continues to filter-feed, but arrests growth until favorable conditions return. Upon release from such conditions, initial recovery was independent of nutrient-responsive, trans-spliced genes, suggesting animal density sensing as a first trigger for resumption of development. Our results demonstrate a role for trans-splicing in the coordinated translational down-regulation of nutrient-responsive genes under limiting conditions.

scholarly journals The origin and evolution of a distinct mechanism of transcription initiation in yeasts

2020 ◽  
Author(s):  
Zhaolian Lu ◽  
Zhenguo Lin
Keyword(s):  
Rna Polymerase Ii ◽  
Transcription Initiation ◽  
Core Promoter ◽  
Model Species ◽  
Initiation Mechanism ◽  
Protein Coding ◽  
Origin And Evolution ◽  
Transcription Start Sites ◽  
Mrna Maturation ◽  
Nucleotide Resolution

ABSTRACTThe molecular process of transcription by RNA Polymerase II is highly conserved among eukaryotes (“classic model”). Intriguingly, a distinct way of locating transcription start sites (TSSs) was found in a budding yeast Saccharomyces cerevisiae (“scanning model”). The origin of the “scanning model” and its underlying genetic mechanisms remain unsolved. Herein, we applied genomic approaches to address these questions. We first identified TSSs at a single-nucleotide resolution for 12 yeast species using the nAnT-iCAGE technique, which significantly improved the annotations of these genomes by providing accurate 5’boundaries of protein-coding genes. We then infer the initiation mechanism of a species based on its TSS maps and genome sequences. We found that the “scanning model” had originated after the split of Yarrowia lipolytica and the rest of budding yeasts. An adenine-rich region immediately upstream of TSS had appeared during the evolution of the “scanning model” species, which might facilitate TSS selection in these species. Both initiation mechanisms share a strong preference for pyrimidine-purine dinucleotides surrounding the TSS. Our results suggested that the purine is required for accurately recruiting the first nucleotide, increasing the chance of being capped during mRNA maturation, which is critical for efficient translation initiation. Based on our findings, we proposed a model of TSS selection for the “scanning model” species. Besides, our study also demonstrated that the intrinsic sequence feature primarily determines the distribution of initiation activities within a core promoter (core promoter shape).

scholarly journals RNA polymerase II-independent recruitment of SPT6L at transcription start sites in Arabidopsis

2019 ◽  
Vol 47 (13) ◽  
pp. 6714-6725 ◽  
Author(s):  
Chen Chen ◽  
Jie Shu ◽  
Chenlong Li ◽  
Raj K Thapa ◽  
Vi Nguyen ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcription Initiation ◽  
Elongation Factor ◽  
Proper Function ◽  
Gene Body ◽  
Transcription Start ◽  
Transcription Start Sites ◽  
Genome Wide ◽  
Yeast Mutants

Abstract SPT6 is a conserved elongation factor that is associated with phosphorylated RNA polymerase II (RNAPII) during transcription. Recent transcriptome analysis in yeast mutants revealed its potential role in the control of transcription initiation at genic promoters. However, the mechanism by which this is achieved and how this is linked to elongation remains to be elucidated. Here, we present the genome-wide occupancy of Arabidopsis SPT6-like (SPT6L) and demonstrate its conserved role in facilitating RNAPII occupancy across transcribed genes. We also further demonstrate that SPT6L enrichment is unexpectedly shifted, from gene body to transcription start site (TSS), when its association with RNAPII is disrupted. Protein domains, required for proper function and enrichment of SPT6L on chromatin, are subsequently identified. Finally, our results suggest that recruitment of SPT6L at TSS is indispensable for its spreading along the gene body during transcription. These findings provide new insights into the mechanisms underlying SPT6L recruitment in transcription and shed light on the coordination between transcription initiation and elongation.

scholarly journals Identification and characterization of Hoxa9 binding sites in hematopoietic cells

Blood ◽  
2012 ◽  
Vol 119 (2) ◽  
pp. 388-398 ◽  
Author(s):  
Yongsheng Huang ◽  
Kajal Sitwala ◽  
Joel Bronstein ◽  
Daniel Sanders ◽  
Monisha Dandekar ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Binding Sites ◽  
Enhancer Activity ◽  
Transcription Start Sites ◽  
Genome Wide ◽  
A Genome ◽  
Evolutionarily Conserved ◽  
P300 Binding ◽  
Histone H3k4

The clustered homeobox proteins play crucial roles in development, hematopoiesis, and leukemia, yet the targets they regulate and their mechanisms of action are poorly understood. Here, we identified the binding sites for Hoxa9 and the Hox cofactor Meis1 on a genome-wide level and profiled their associated epigenetic modifications and transcriptional targets. Hoxa9 and the Hox cofactor Meis1 cobind at hundreds of highly evolutionarily conserved sites, most of which are distant from transcription start sites. These sites show high levels of histone H3K4 monomethylation and CBP/P300 binding characteristic of enhancers. Furthermore, a subset of these sites shows enhancer activity in transient transfection assays. Many Hoxa9 and Meis1 binding sites are also bound by PU.1 and other lineage-restricted transcription factors previously implicated in establishment of myeloid enhancers. Conditional Hoxa9 activation is associated with CBP/P300 recruitment, histone acetylation, and transcriptional activation of a network of proto-oncogenes, including Erg, Flt3, Lmo2, Myb, and Sox4. Collectively, this work suggests that Hoxa9 regulates transcription by interacting with enhancers of genes important for hematopoiesis and leukemia.

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