Washington University in St. Louis Washington University Open Scholarship Arts & Sciences Electronic Theses and Dissertations Arts & Sciences Winter 12-15-2018 The Essential Roles of the Chromatin Factor Gon4l in Heart Development Terin Elise Budine Washington University in St. Louis Follow this and additional works at: https://openscholarship.wustl.edu/art_sci_etds Part of the Developmental Biology Commons Recommended Citation Budine, Terin Elise, "The Essential Roles of the Chromatin Factor Gon4l in Heart Development" (2018). Arts & Sciences Electronic Theses and Dissertations. 1689. https://openscholarship.wustl.edu/art_sci_etds/1689 This Dissertation is brought to you for free and open access by the Arts & Sciences at Washington University Open Scholarship. It has been accepted for inclusion in Arts & Sciences Electronic Theses and Dissertations by an authorized administrator of Washington University Open Scholarship. For more information, please contact [email protected]. WASHINGTON UNIVERSITY IN ST. LOUS Division of Biology and Biomedical Sciences Developmental, Regenerative, and Stem Cell Biology Dissertation Examination Committee: Lilianna Solnica-Krezel, Chair Kristen Kroll, Co-Chair Patrick Jay Stacey Rentschler Andrew Yoo The Essential Roles of the Chromatin Factor Gon4l in Heart Development by Terin Elise Budine A dissertation presented to The Graduate School of Washington University in partial fulfillment of the requirements for the degree of Doctor of Philosophy December 2018 St. Louis, Missouri © 2018, Terin Budine i Table of Contents List of Figures ........................................................................................................................................... v List of Abbreviations ............................................................................................................................ vii Acknowledgements ................................................................................................................................ xi Abstract of the Dissertation ................................................................................................................ xv Chapter 1: Introduction ........................................................................................................................ 1 1.1 Congenital Heart Defects ............................................................................................................................ 1 1.2 Mesoderm specification and patterning.................................................................................................. 4 1.3 Anterior Lateral Plate Mesoderm Patterning .................................................................................... 11 1.4 Bilteral Heart Field Merging and Heart Looping ............................................................................. 13 1.5 Expansion of the Cardiomyocyte Population ..................................................................................... 14 1.6 Cardiac Chamber Patterning ................................................................................................................. 16 1.7 Epigenetic Regulation of Heart Development .................................................................................... 17 1.8 Gon4l ............................................................................................................................................................ 20 1.8.1 gon-4 in C. elegans ............................................................................................................................................ 21 1.8.2 gon4l/udu in Zebrafish ..................................................................................................................................... 23 1.8.3 Gon4l in Mouse .................................................................................................................................................. 24 1.9 Links Between Gon4l and Heart Development .................................................................................. 25 1.10 Objectives, Results, and Significance of Thesis................................................................................ 27 Chapter 2: Chromatin factor Gon4l aides germ layer patterning ............................................. 29 2.1 Abstract ....................................................................................................................................................... 29 2.2 Introduction ................................................................................................................................................ 29 2.3 Material and Methods .............................................................................................................................. 31 ii 2.4 Results .......................................................................................................................................................... 36 2.4.1 Loss of maternal and zygotic udu expression affects expression of dorsal-ventral patterning genes during early embryogenesis ........................................................................................................................... 36 2.4.2 MZudu embryos fail to pattern the mesoderm .......................................................................................... 41 2.4.3 MZudu embryos present abnormal development of mesoderm derived organs and tissues .............................................................................................................. 45 2.4.4 Heart development is severely impaired in MZudu mutant embryos ................................................ 48 2.4.5 Gon4l is required both cell-autonomously and non-cell-autonomously in heart development . 51 2.4.6 Gon4l Motif Finding ......................................................................................................................................... 54 2.5 Discussion .................................................................................................................................................... 58 2.6 Supplemental Information ...................................................................................................................... 61 Chapter 3: Gon4l/Udu Regulates Cardiomyocyte Proliferation and Maintenance of Ventricular Chamber Identity During Zebrafish Development ................................................ 63 3.1 Abstract ....................................................................................................................................................... 63 3.2 Introduction ................................................................................................................................................ 64 3.3 Materials and Methods ............................................................................................................................ 67 3.4 Results .......................................................................................................................................................... 73 3.4.1 Zygotic mutations in udu result in reduced cardiomyocyte number and decreased ventricular fate ..................................................................................................................................................................................... 73 3.4.2 Cell death is not responsible for the reduced cardiomyocyte numbers in udu mutants. .............. 78 3.4.3 Cardiomyocyte proliferation is reduced in udu mutants ........................................................................ 83 3.4.4 Expression of nkx2.5 and nkx2.7 is reduced in udu mutants following heart tube formation .... 87 3.4.5 udu genetically interacts with nkx2.5 maintain ventricular identity................................................... 90 3.4.6 Overexpression of nkx2.5 is not sufficient to suppress udu heart defects ........................................ 92 3.5 Discussion .................................................................................................................................................... 96 iii 3.6 Supplemental Information .................................................................................................................... 101 Chapter 4: Discussion ........................................................................................................................ 105 4.1 Perspective ................................................................................................................................................ 105 4.2 Gon4l in germ layer induction and mesoderm patterning ............................................................ 107 4.3 udu and nkx2.5 ......................................................................................................................................... 109 4.4 Zygotic functions of Gon4l .................................................................................................................... 111 4.5 Defining how Gon4l modifies the epigenetic landscape ................................................................. 112 4.6 The roles of GON4L in human disease and development ............................................................. 113 4.7 Conclusions ............................................................................................................................................... 114 References .........................................................................................................................................