Cargando…

The Gene Regulatory Network of Lens Induction Is Wired through Meis-Dependent Shadow Enhancers of Pax6

Lens induction is a classical developmental model allowing investigation of cell specification, spatiotemporal control of gene expression, as well as how transcription factors are integrated into highly complex gene regulatory networks (GRNs). Pax6 represents a key node in the gene regulatory networ...

Descripción completa

Detalles Bibliográficos
Autores principales: Antosova, Barbora, Smolikova, Jana, Klimova, Lucie, Lachova, Jitka, Bendova, Michaela, Kozmikova, Iryna, Machon, Ondrej, Kozmik, Zbynek
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5137874/
https://www.ncbi.nlm.nih.gov/pubmed/27918583
http://dx.doi.org/10.1371/journal.pgen.1006441
_version_ 1782471971845439488
author Antosova, Barbora
Smolikova, Jana
Klimova, Lucie
Lachova, Jitka
Bendova, Michaela
Kozmikova, Iryna
Machon, Ondrej
Kozmik, Zbynek
author_facet Antosova, Barbora
Smolikova, Jana
Klimova, Lucie
Lachova, Jitka
Bendova, Michaela
Kozmikova, Iryna
Machon, Ondrej
Kozmik, Zbynek
author_sort Antosova, Barbora
collection PubMed
description Lens induction is a classical developmental model allowing investigation of cell specification, spatiotemporal control of gene expression, as well as how transcription factors are integrated into highly complex gene regulatory networks (GRNs). Pax6 represents a key node in the gene regulatory network governing mammalian lens induction. Meis1 and Meis2 homeoproteins are considered as essential upstream regulators of Pax6 during lens morphogenesis based on their interaction with the ectoderm enhancer (EE) located upstream of Pax6 transcription start site. Despite this generally accepted regulatory pathway, Meis1-, Meis2- and EE-deficient mice have surprisingly mild eye phenotypes at placodal stage of lens development. Here, we show that simultaneous deletion of Meis1 and Meis2 in presumptive lens ectoderm results in arrested lens development in the pre-placodal stage, and neither lens placode nor lens is formed. We found that in the presumptive lens ectoderm of Meis1/Meis2 deficient embryos Pax6 expression is absent. We demonstrate using chromatin immunoprecipitation (ChIP) that in addition to EE, Meis homeoproteins bind to a remote, ultraconserved SIMO enhancer of Pax6. We further show, using in vivo gene reporter analyses, that the lens-specific activity of SIMO enhancer is dependent on the presence of three Meis binding sites, phylogenetically conserved from man to zebrafish. Genetic ablation of EE and SIMO enhancers demostrates their requirement for lens induction and uncovers an apparent redundancy at early stages of lens development. These findings identify a genetic requirement for Meis1 and Meis2 during the early steps of mammalian eye development. Moreover, they reveal an apparent robustness in the gene regulatory mechanism whereby two independent "shadow enhancers" maintain critical levels of a dosage-sensitive gene, Pax6, during lens induction.
format Online
Article
Text
id pubmed-5137874
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-51378742016-12-21 The Gene Regulatory Network of Lens Induction Is Wired through Meis-Dependent Shadow Enhancers of Pax6 Antosova, Barbora Smolikova, Jana Klimova, Lucie Lachova, Jitka Bendova, Michaela Kozmikova, Iryna Machon, Ondrej Kozmik, Zbynek PLoS Genet Research Article Lens induction is a classical developmental model allowing investigation of cell specification, spatiotemporal control of gene expression, as well as how transcription factors are integrated into highly complex gene regulatory networks (GRNs). Pax6 represents a key node in the gene regulatory network governing mammalian lens induction. Meis1 and Meis2 homeoproteins are considered as essential upstream regulators of Pax6 during lens morphogenesis based on their interaction with the ectoderm enhancer (EE) located upstream of Pax6 transcription start site. Despite this generally accepted regulatory pathway, Meis1-, Meis2- and EE-deficient mice have surprisingly mild eye phenotypes at placodal stage of lens development. Here, we show that simultaneous deletion of Meis1 and Meis2 in presumptive lens ectoderm results in arrested lens development in the pre-placodal stage, and neither lens placode nor lens is formed. We found that in the presumptive lens ectoderm of Meis1/Meis2 deficient embryos Pax6 expression is absent. We demonstrate using chromatin immunoprecipitation (ChIP) that in addition to EE, Meis homeoproteins bind to a remote, ultraconserved SIMO enhancer of Pax6. We further show, using in vivo gene reporter analyses, that the lens-specific activity of SIMO enhancer is dependent on the presence of three Meis binding sites, phylogenetically conserved from man to zebrafish. Genetic ablation of EE and SIMO enhancers demostrates their requirement for lens induction and uncovers an apparent redundancy at early stages of lens development. These findings identify a genetic requirement for Meis1 and Meis2 during the early steps of mammalian eye development. Moreover, they reveal an apparent robustness in the gene regulatory mechanism whereby two independent "shadow enhancers" maintain critical levels of a dosage-sensitive gene, Pax6, during lens induction. Public Library of Science 2016-12-05 /pmc/articles/PMC5137874/ /pubmed/27918583 http://dx.doi.org/10.1371/journal.pgen.1006441 Text en © 2016 Antosova et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Antosova, Barbora
Smolikova, Jana
Klimova, Lucie
Lachova, Jitka
Bendova, Michaela
Kozmikova, Iryna
Machon, Ondrej
Kozmik, Zbynek
The Gene Regulatory Network of Lens Induction Is Wired through Meis-Dependent Shadow Enhancers of Pax6
title The Gene Regulatory Network of Lens Induction Is Wired through Meis-Dependent Shadow Enhancers of Pax6
title_full The Gene Regulatory Network of Lens Induction Is Wired through Meis-Dependent Shadow Enhancers of Pax6
title_fullStr The Gene Regulatory Network of Lens Induction Is Wired through Meis-Dependent Shadow Enhancers of Pax6
title_full_unstemmed The Gene Regulatory Network of Lens Induction Is Wired through Meis-Dependent Shadow Enhancers of Pax6
title_short The Gene Regulatory Network of Lens Induction Is Wired through Meis-Dependent Shadow Enhancers of Pax6
title_sort gene regulatory network of lens induction is wired through meis-dependent shadow enhancers of pax6
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5137874/
https://www.ncbi.nlm.nih.gov/pubmed/27918583
http://dx.doi.org/10.1371/journal.pgen.1006441
work_keys_str_mv AT antosovabarbora thegeneregulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT smolikovajana thegeneregulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT klimovalucie thegeneregulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT lachovajitka thegeneregulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT bendovamichaela thegeneregulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT kozmikovairyna thegeneregulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT machonondrej thegeneregulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT kozmikzbynek thegeneregulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT antosovabarbora generegulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT smolikovajana generegulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT klimovalucie generegulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT lachovajitka generegulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT bendovamichaela generegulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT kozmikovairyna generegulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT machonondrej generegulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6
AT kozmikzbynek generegulatorynetworkoflensinductioniswiredthroughmeisdependentshadowenhancersofpax6