scholarly journals Endodermal Maternal Transcription Factors Establish Super-Enhancers during Zygotic Genome Activation

Cell Reports ◽  
2019 ◽  
Vol 27 (10) ◽  
pp. 2962-2977.e5 ◽  
Author(s):  
Kitt D. Paraiso ◽  
Ira L. Blitz ◽  
Masani Coley ◽  
Jessica Cheung ◽  
Norihiro Sudou ◽  
...  
2019 ◽  
Author(s):  
Máté Pálfy ◽  
Gunnar Schulze ◽  
Eivind Valen ◽  
Nadine L. Vastenhouw

ABSTRACTIn many organisms, early embryonic development is driven by maternally provided factors until the controlled onset of transcription during zygotic genome activation. The regulation of chromatin accessibility and its relationship to gene activity during this transition remains poorly understood. Here, we generated chromatin accessibility maps from genome activation until the onset of lineage specification. During this period, chromatin accessibility increases at regulatory elements. This increase is independent of RNA polymerase II-mediated transcription, with the exception of the hyper-transcribed miR-430 locus. Instead, accessibility often precedes the transcription of associated genes. Loss of the maternal transcription factors Pou5f3, Sox19b, and Nanog, which are known to be required for zebrafish genome activation, results in decreased accessibility at regulatory elements. Importantly, the accessibility of regulatory regions, especially when established by Pou5f3, Sox19b and Nanog, is predictive for future transcription. Our results show that the maternally provided transcription factors Pou5f3, Sox19b, and Nanog open up chromatin and prime genes for activity during zygotic genome activation in zebrafish.


2019 ◽  
Author(s):  
William Stanney ◽  
Franck Ladam ◽  
Ian J. Donaldson ◽  
Teagan J. Parsons ◽  
René Maehr ◽  
...  

SUMMARYAnimal embryogenesis is initiated by maternal factors, but zygotic genome activation (ZGA) shifts control to the embryo at early blastula stages. ZGA is thought to be mediated by specialized maternally deposited transcription factors (TFs), but here we demonstrate that NF-Y and TALE – TFs with known later roles in embryogenesis – co-occupy unique genomic elements at zebrafish ZGA. We show that these elements are selectively associated with early-expressed genes involved in transcriptional regulation and possess enhancer activity in vivo. In contrast, we find that elements individually occupied by either NF-Y or TALE are associated with genes acting later in development – such that NF-Y controls a cilia gene expression program while TALE TFs control expression of hox genes. We conclude that NF-Y and TALE have a shared role at ZGA, but separate roles later during development, demonstrating that combinations of known TFs can regulate subsets of key developmental genes at vertebrate ZGA.


2017 ◽  
Vol 49 (6) ◽  
pp. 941-945 ◽  
Author(s):  
Alberto De Iaco ◽  
Evarist Planet ◽  
Andrea Coluccio ◽  
Sonia Verp ◽  
Julien Duc ◽  
...  

2020 ◽  
Author(s):  
Jingyue Ellie Duan ◽  
Leila E. Rieder ◽  
Annie Huang ◽  
William T. Jordan ◽  
Mary McKenney ◽  
...  

ABSTRACTBecause zygotic genome activation (ZGA) is an essential process across metazoans, it is key to evolve multiple pioneer transcription factors (TFs) to protect organisms from loss of a single factor. Pioneer TF Zelda (ZLD) is the only known factor which increases accessibility of chromatin to promote ZGA in the early Drosophila embryo. However, many genomic loci remain accessible without ZLD and have GA-rich motifs. Therefore, we hypothesized that other pioneer TFs that function with ZLD have not yet been identified in early embryos, especially those that bind to GA-rich motifs, such as CLAMP (Chromatin-linked adaptor for Male-specific lethal MSL proteins). Here, we determine that CLAMP is a novel pioneer TF which interacts directly with nucleosomes, regulates zygotic genome transcription, promotes chromatin accessibility, and facilitates the binding of ZLD to promoters. Thus, the maternal factor CLAMP functions with ZLD as a pioneer TF to open chromatin and drive zygotic genome activation.


Genetics ◽  
2021 ◽  
Author(s):  
Megan M Colonnetta ◽  
Juan E Abrahante ◽  
Paul Schedl ◽  
Daryl M Gohl ◽  
Girish Deshpande

Abstract Embryonic patterning is critically dependent on zygotic genome activation (ZGA). In Drosophila melanogaster embryos, the pioneer factor Zelda directs ZGA, possibly in conjunction with other factors. Here we have explored novel involvement of Chromatin-Linked Adapter for MSL Proteins (CLAMP) during ZGA. CLAMP binds thousands of sites genome-wide throughout early embryogenesis. Interestingly, CLAMP relocates to target promoter sequences across the genome when ZGA is initiated. Although there is a considerable overlap between CLAMP and Zelda binding sites, the proteins display distinct temporal dynamics. To assess whether CLAMP occupancy affects gene expression, we analyzed transcriptomes of embryos zygotically compromised for either clamp or zelda and found that transcript levels of many zygotically-activated genes are similarly affected. Importantly, compromising either clamp or zelda disrupted the expression of critical segmentation and sex determination genes bound by CLAMP (and Zelda). Furthermore, clamp knockdown embryos recapitulate other phenotypes observed in Zelda-depleted embryos, including nuclear division defects, centrosome aberrations, and a disorganized actomyosin network. Based on these data, we propose that CLAMP acts in concert with Zelda to regulate early zygotic transcription.


2017 ◽  
Vol 42 (4) ◽  
pp. 316-332 ◽  
Author(s):  
David Jukam ◽  
S. Ali M. Shariati ◽  
Jan M. Skotheim

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