Gli3 utilizes Hand2 to synergistically regulate tissue-specific transcriptional networks
- Cincinnati Children's Hospital Medical Center, United States
- The Jackson Laboratory, United States
- University of Basel, Switzerland
- Harvard University, United States
Abstract
Despite a common understanding that Gli TFs are utilized to reiterate a Hh morphogen gradient, genetic analyses suggest craniofacial development does not completely fit this paradigm. Using the mouse model (Mus musculus), we demonstrated that rather than being driven by a Hh threshold, robust Gli3 transcriptional activity during skeletal and glossal development required interaction with the basic helix-loop-helix TF Hand2. Not only did genetic and expression data support a co-factorial relationship, but genomic analysis revealed that Gli3 and Hand2 were enriched at regulatory elements for genes essential for mandibular patterning and development. Interestingly, motif analysis at sites co-occupied by Gli3 and Hand2 uncovered mandibular-specific, low-affinity, 'divergent' Gli binding motifs (<strong>d</strong>GBMs). Functional validation revealed these <strong>d</strong>GBMs conveyed synergistic activation of Gli targets essential for mandibular patterning and development. In summary, this work elucidates a novel, sequence-dependent mechanism for Gli transcriptional activity within the craniofacial complex that is independent of a graded Hh signal.
Data availability
Sequencing data have been deposited in GEO under accession codes GSE141431, GSE141173.ChIP data have been deposited in GEO under accession code GSE146961All data generated or analyzed during this study are included in the manuscript and supporting files. Source data files have been provided for Figures 1,5,8,9, Figure 1-figure supplement 1, Figure 8-figure supplement 2, and Figure 9-figure supplement 1
-
Single cell sequencing of dissected mouse mandibular prominence at embryonic day e11.5 and e13.5NCBI Gene Expression Omnibus, GSE141173.
-
Gli3 and Hand2 ChIP-sequencing of developing face and mandibular prominenceNCBI Gene Expression Omnibus, GSE146961.
-
Genome-wide candidate HAND2 target regions in mouse embryonic tissuesNCBI Gene Expression Omnibus, GSE55707.
Article and author information
Author details
Samantha A Brugmann
Funding
National Institutes of Health (R35DE027557)
- Samantha A Brugmann
National Institutes of Health (R01GM124251)
- Kevin A Peterson
National Institutes of Health (F31DE027872)
- Kelsey H Elliott
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All of the animals were handled according to approved institutional animal care and use committee (IACUC) protocols (IACUC2017-0063) of Cincinnati Children's Hospital Medical Center.
Copyright
© 2020, Elliott et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 2,554
- views
-
- 358
- downloads
-
- 18
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Further reading
-
- Developmental Biology
Human autonomic neuronal cell models are emerging as tools for modelling diseases such as cardiac arrhythmias. In this systematic review, we compared thirty-three articles applying fourteen different protocols to generate sympathetic neurons and three different procedures to produce parasympathetic neurons. All methods involved the differentiation of human pluripotent stem cells, and none employed permanent or reversible cell immortalization. Almost all protocols were reproduced in multiple pluripotent stem cell lines, and over half show evidence of neural firing capacity. Common limitations in the field are a lack of three-dimensional models and models including multiple cell types. Sympathetic neuron differentiation protocols largely mirrored embryonic development, with the notable absence of migration, axon extension, and target-specificity cues. Parasympathetic neuron differentiation protocols may be improved by including several embryonic cues promoting cell survival, cell maturation, or ion channel expression. Moreover, additional markers to define parasympathetic neurons in vitro may support the validity of these protocols. Nonetheless, four sympathetic neuron differentiation protocols and one parasympathetic neuron differentiation protocol reported more than two thirds of cells expressing autonomic neuron markers. Altogether, these protocols promise to open new research avenues of human autonomic neuron development and disease modelling.
-
- Developmental Biology
- Genetics and Genomics
The establishment and growth of the arterial endothelium require the coordinated expression of numerous genes. However, regulation of this process is not yet fully understood. Here, we combined in silico analysis with transgenic mice and zebrafish models to characterize arterial-specific enhancers associated with eight key arterial identity genes (Acvrl1/Alk1, Cxcr4, Cxcl12, Efnb2, Gja4/Cx37, Gja5/Cx40, Nrp1, and Unc5b). Next, to elucidate the regulatory pathways upstream of arterial gene transcription, we investigated the transcription factors binding each arterial enhancer compared to a similar assessment of non-arterial endothelial enhancers. These results found that binding of SOXF and ETS factors was a common occurrence at both arterial and pan-endothelial enhancers, suggesting neither are sufficient to direct arterial specificity. Conversely, FOX motifs independent of ETS motifs were over-represented at arterial enhancers. Further, MEF2 and RBPJ binding was enriched but not ubiquitous at arterial enhancers, potentially linked to specific patterns of behaviour within the arterial endothelium. Lastly, there was no shared or arterial-specific signature for WNT-associated TCF/LEF, TGFβ/BMP-associated SMAD1/5 and SMAD2/3, shear stress-associated KLF4, or venous-enriched NR2F2. This cohort of well-characterized and in vivo-verified enhancers can now provide a platform for future studies into the interaction of different transcriptional and signaling pathways with arterial gene expression.
