Robert K. Ho

Research Summary
The zebrafish, Danio rerio, is a relatively simple vertebrate whose potential as a model system for developmental studies is only recently being realized. Embryos are easy to obtain in large numbers, develop external to the mother in fresh water and are optically transparent throughout the early stages of development. These features make the zebrafish embryo easily accessible to experimental manipulations such as the microinjection of lineage tracer molecules, cell ablations and cell transplantation. In addition to being an excellent embryological preparation, the zebrafish has an extensive history of genetic analyses and many interesting mutations have already been isolated. The ability to combine a workable genetics with an accessible embryology is perhaps the most advantageous feature of working with the zebrafish and has provided us with many novel insights into vertebrate development. The theme of the work being performed in the laboratory is to address classical problems of vertebrate embryogenesis using modern techniques in the zebrafish embryo. The general goal is to gain insights into the cellular, molecular and genetic mechanisms leading to the assignment of cell fate and, ultimately, to the formation of a complex vertebrate body plan. We are especially interested in the processes leading to the specification of the embryonic body axes and how the movements of individual cells within the embryo influence/correlate with cell fate decisions.
  1. Boyle-Anderson EAT, Mao Q, Ho RK. Tbx5a and Tbx5b paralogues act in combination to control separate vectors of migration in the fin field of zebrafish. Dev Biol. 2022 01; 481:201-214. View in: PubMed

  2. Mao LMF, Boyle Anderson EAT, Ho RK. Anterior lateral plate mesoderm gives rise to multiple tissues and requires tbx5a function in left-right asymmetry, migration dynamics, and cell specification of late-addition cardiac cells. Dev Biol. 2021 04; 472:52-66. View in: PubMed

  3. Quintanilla CA, Ho RK. The Cdx transcription factors and retinoic acid play parallel roles in antero-posterior position of the pectoral fin field during gastrulation. Mech Dev. 2020 12; 164:103644. View in: PubMed

  4. Stewart TA, Bonilla MM, Ho RK, Hale ME. Adipose fin development and its relation to the evolutionary origins of median fins. Sci Rep. 2019 01 24; 9(1):512. View in: PubMed

  5. Boyle Anderson EAT, Ho RK. A transcriptomics analysis of the Tbx5 paralogues in zebrafish. PLoS One. 2018; 13(12):e0208766. View in: PubMed

  6. Steimle JD, Rankin SA, Slagle CE, Bekeny J, Rydeen AB, Chan SS, Kweon J, Yang XH, Ikegami K, Nadadur RD, Rowton M, Hoffmann AD, Lazarevic S, Thomas W, Boyle Anderson EAT, Horb ME, Luna-Zurita L, Ho RK, Kyba M, Jensen B, Zorn AM, Conlon FL, Moskowitz IP. Evolutionarily conserved Tbx5-Wnt2/2b pathway orchestrates cardiopulmonary development. Proc Natl Acad Sci U S A. 2018 11 06; 115(45):E10615-E10624. View in: PubMed

  7. Zhao BS, Wang X, Beadell AV, Lu Z, Shi H, Kuuspalu A, Ho RK, He C. m6A-dependent maternal mRNA clearance facilitates zebrafish maternal-to-zygotic transition. Nature. 2017 02 23; 542(7642):475-478. View in: PubMed

  8. Chang J, Skromne I, Ho RK. CDX4 and retinoic acid interact to position the hindbrain-spinal cord transition. Dev Biol. 2016 Feb 15; 410(2):178-189. View in: PubMed

  9. Mao Q, Stinnett HK, Ho RK. Asymmetric cell convergence-driven zebrafish fin bud initiation and pre-pattern requires Tbx5a control of a mesenchymal Fgf signal. Development. 2015 Dec 15; 142(24):4329-39. View in: PubMed

  10. Warga RM, Mueller RL, Ho RK, Kane DA. Zebrafish Tbx16 regulates intermediate mesoderm cell fate by attenuating Fgf activity. Dev Biol. 2013 Nov 01; 383(1):75-89. View in: PubMed

  11. Green MH, Ho RK, Hale ME. Movement and function of the pectoral fins of the larval zebrafish (Danio rerio) during slow swimming. J Exp Biol. 2011 Sep 15; 214(Pt 18):3111-23. View in: PubMed

  12. Mueller RL, Huang C, Ho RK. Spatio-temporal regulation of Wnt and retinoic acid signaling by tbx16/spadetail during zebrafish mesoderm differentiation. BMC Genomics. 2010 Sep 09; 11:492. View in: PubMed

  13. Elsen GE, Choi LY, Prince VE, Ho RK. The autism susceptibility gene met regulates zebrafish cerebellar development and facial motor neuron migration. Dev Biol. 2009 Nov 01; 335(1):78-92. View in: PubMed

  14. Warga RM, Kane DA, Ho RK. Fate mapping embryonic blood in zebrafish: multi- and unipotential lineages are segregated at gastrulation. Dev Cell. 2009 May; 16(5):744-55. View in: PubMed

  15. Ahn D, Ho RK. Tri-phasic expression of posterior Hox genes during development of pectoral fins in zebrafish: implications for the evolution of vertebrate paired appendages. Dev Biol. 2008 Oct 01; 322(1):220-33. View in: PubMed

  16. Skromne I, Thorsen D, Hale M, Prince VE, Ho RK. Repression of the hindbrain developmental program by Cdx factors is required for the specification of the vertebrate spinal cord. Development. 2007 Jun; 134(11):2147-58. View in: PubMed

  17. Hurley IA, Mueller RL, Dunn KA, Schmidt EJ, Friedman M, Ho RK, Prince VE, Yang Z, Thomas MG, Coates MI. A new time-scale for ray-finned fish evolution. Proc Biol Sci. 2007 Feb 22; 274(1609):489-98. View in: PubMed

  18. Walton RZ, Bruce AE, Olivey HE, Najib K, Johnson V, Earley JU, Ho RK, Svensson EC. Fog1 is required for cardiac looping in zebrafish. Dev Biol. 2006 Jan 15; 289(2):482-93. View in: PubMed

  19. Oates AC, Rohde LA, Ho RK. Generation of segment polarity in the paraxial mesoderm of the zebrafish through a T-box-dependent inductive event. Dev Biol. 2005 Jul 01; 283(1):204-14. View in: PubMed

  20. Oates AC, Mueller C, Ho RK. Cooperative function of deltaC and her7 in anterior segment formation. Dev Biol. 2005 Apr 01; 280(1):133-49. View in: PubMed

  21. Bruce AE, Howley C, Dixon Fox M, Ho RK. T-box gene eomesodermin and the homeobox-containing Mix/Bix gene mtx2 regulate epiboly movements in the zebrafish. Dev Dyn. 2005 May; 233(1):105-14. View in: PubMed

  22. Rohde LA, Oates AC, Ho RK. A crucial interaction between embryonic red blood cell progenitors and paraxial mesoderm revealed in spadetail embryos. Dev Cell. 2004 Aug; 7(2):251-62. View in: PubMed

  23. Bruce AE, Howley C, Zhou Y, Vickers SL, Silver LM, King ML, Ho RK. The maternally expressed zebrafish T-box gene eomesodermin regulates organizer formation. Development. 2003 Nov; 130(22):5503-17. View in: PubMed

  24. Piotrowski T, Ahn DG, Schilling TF, Nair S, Ruvinsky I, Geisler R, Rauch GJ, Haffter P, Zon LI, Zhou Y, Foott H, Dawid IB, Ho RK. The zebrafish van gogh mutation disrupts tbx1, which is involved in the DiGeorge deletion syndrome in humans. Development. 2003 Oct; 130(20):5043-52. View in: PubMed

  25. Ahn DG, Kourakis MJ, Rohde LA, Silver LM, Ho RK. T-box gene tbx5 is essential for formation of the pectoral limb bud. Nature. 2002 Jun 13; 417(6890):754-8. View in: PubMed

  26. Lieschke GJ, Oates AC, Paw BH, Thompson MA, Hall NE, Ward AC, Ho RK, Zon LI, Layton JE. Zebrafish SPI-1 (PU.1) marks a site of myeloid development independent of primitive erythropoiesis: implications for axial patterning. Dev Biol. 2002 Jun 15; 246(2):274-95. View in: PubMed

  27. Oates AC, Ho RK. Hairy/E(spl)-related (Her) genes are central components of the segmentation oscillator and display redundancy with the Delta/Notch signaling pathway in the formation of anterior segmental boundaries in the zebrafish. Development. 2002 Jun; 129(12):2929-46. View in: PubMed

  28. Keegan BR, Feldman JL, Lee DH, Koos DS, Ho RK, Stainier DY, Yelon D. The elongation factors Pandora/Spt6 and Foggy/Spt5 promote transcription in the zebrafish embryo. Development. 2002 Apr; 129(7):1623-32. View in: PubMed

  29. Oates AC, Pratt SJ, Vail B. The zebrafish klf gene family. Blood. 2001 Sep 15; 98(6):1792-801. View in: PubMed

  30. Bruce AE, Oates AC, Prince VE, Ho RK. Additional hox clusters in the zebrafish: divergent expression patterns belie equivalent activities of duplicate hoxB5 genes. Evol Dev. 2001 May-Jun; 3(3):127-44. View in: PubMed

  31. Prince VE, Holley SA, Bally-Cuif L, Prabhakaran B, Oates AC, Ho RK, Vogt TF. Zebrafish lunatic fringe demarcates segmental boundaries. Mech Dev. 2001 Jul; 105(1-2):175-80. View in: PubMed

  32. Ahn DG, Ruvinsky I, Oates AC, Silver LM, Ho RK. tbx20, a new vertebrate T-box gene expressed in the cranial motor neurons and developing cardiovascular structures in zebrafish. Mech Dev. 2000 Jul; 95(1-2):253-8. View in: PubMed

  33. Oates AC, Bruce AE, Ho RK. Too much interference: injection of double-stranded RNA has nonspecific effects in the zebrafish embryo. Dev Biol. 2000 Aug 01; 224(1):20-8. View in: PubMed

  34. Yelon D, Ticho B, Halpern ME, Ruvinsky I, Ho RK, Silver LM, Stainier DY. The bHLH transcription factor hand2 plays parallel roles in zebrafish heart and pectoral fin development. Development. 2000 Jun; 127(12):2573-82. View in: PubMed

  35. Howley C, Ho RK. mRNA localization patterns in zebrafish oocytes. Mech Dev. 2000 Apr; 92(2):305-9. View in: PubMed

  36. Ruvinsky I, Oates AC, Silver LM, Ho RK. The evolution of paired appendages in vertebrates: T-box genes in the zebrafish. Dev Genes Evol. 2000 Feb; 210(2):82-91. View in: PubMed

  37. Koos DS, Ho RK. The nieuwkoid/dharma homeobox gene is essential for bmp2b repression in the zebrafish pregastrula. Dev Biol. 1999 Nov 15; 215(2):190-207. View in: PubMed

  38. Oates AC, Wollberg P, Pratt SJ, Paw BH, Johnson SL, Ho RK, Postlethwait JH, Zon LI, Wilks AF. Zebrafish stat3 is expressed in restricted tissues during embryogenesis and stat1 rescues cytokine signaling in a STAT1-deficient human cell line. Dev Dyn. 1999 Aug; 215(4):352-70. View in: PubMed

  39. Roy MN, Prince VE, Ho RK. Heat shock produces periodic somitic disturbances in the zebrafish embryo. Mech Dev. 1999 Jul; 85(1-2):27-34. View in: PubMed

  40. Amores A, Force A, Yan YL, Joly L, Amemiya C, Fritz A, Ho RK, Langeland J, Prince V, Wang YL, Westerfield M, Ekker M, Postlethwait JH. Zebrafish hox clusters and vertebrate genome evolution. Science. 1998 Nov 27; 282(5394):1711-4. View in: PubMed

  41. Koos DS, Ho RK. The nieuwkoid gene characterizes and mediates a Nieuwkoop-center-like activity in the zebrafish. Curr Biol. 1998 Nov 05; 8(22):1199-206. View in: PubMed

  42. Prince VE, Price AL, Ho RK. Hox gene expression reveals regionalization along the anteroposterior axis of the zebrafish notochord. Dev Genes Evol. 1998 Nov; 208(9):517-22. View in: PubMed

  43. Bally-Cuif L, Schatz WJ, Ho RK. Characterization of the zebrafish Orb/CPEB-related RNA binding protein and localization of maternal components in the zebrafish oocyte. Mech Dev. 1998 Sep; 77(1):31-47. View in: PubMed

  44. Ruvinsky I, Silver LM, Ho RK. Characterization of the zebrafish tbx16 gene and evolution of the vertebrate T-box family. Dev Genes Evol. 1998 Apr; 208(2):94-9. View in: PubMed

  45. Kozlowski DJ, Murakami T, Ho RK, Weinberg ES. Regional cell movement and tissue patterning in the zebrafish embryo revealed by fate mapping with caged fluorescein. Biochem Cell Biol. 1997; 75(5):551-62. View in: PubMed

  46. Prince VE, Joly L, Ekker M, Ho RK. Zebrafish hox genes: genomic organization and modified colinear expression patterns in the trunk. Development. 1998 Feb; 125(3):407-20. View in: PubMed

  47. Prince VE, Moens CB, Kimmel CB, Ho RK. Zebrafish hox genes: expression in the hindbrain region of wild-type and mutants of the segmentation gene, valentino. Development. 1998 Feb; 125(3):393-406. View in: PubMed

  48. Kanki JP, Ho RK. The development of the posterior body in zebrafish. Development. 1997 Feb; 124(4):881-93. View in: PubMed

  49. Halpern ME, Thisse C, Ho RK, Thisse B, Riggleman B, Trevarrow B, Weinberg ES, Postlethwait JH, Kimmel CB. Cell-autonomous shift from axial to paraxial mesodermal development in zebrafish floating head mutants. Development. 1995 Dec; 121(12):4257-64. View in: PubMed

  50. Halpern ME, Ho RK, Walker C, Kimmel CB. Induction of muscle pioneers and floor plate is distinguished by the zebrafish no tail mutation. Cell. 1993 Oct 08; 75(1):99-111. View in: PubMed

  51. Ho RK, Kimmel CB. Commitment of cell fate in the early zebrafish embryo. Science. 1993 Jul 02; 261(5117):109-11. View in: PubMed

  52. Sepich DS, Ho RK, Westerfield M. Autonomous expression of the nic1 acetylcholine receptor mutation in zebrafish muscle cells. Dev Biol. 1994 Jan; 161(1):84-90. View in: PubMed

  53. Taghert PH, Bastiani MJ, Ho RK, Goodman CS. Guidance of pioneer growth cones: filopodial contacts and coupling revealed with an antibody to Lucifer Yellow. Dev Biol. 1982 Dec; 94(2):391-9. View in: PubMed

  54. Ho RK, Ball EE, Goodman CS. Muscle pioneers: large mesodermal cells that erect a scaffold for developing muscles and motoneurones in grasshopper embryos. Nature. 1983 Jan 06; 301(5895):66-9. View in: PubMed

  55. Ho RK, Goodman CS. Peripheral pathways are pioneered by an array of central and peripheral neurones in grasshopper embryos. Nature. 1982 Jun 03; 297(5865):404-6. View in: PubMed

  56. Ball EE, Ho RK, Goodman CS. Muscle development in the grasshopper embryo. I. Muscles, nerves, and apodemes in the metathoracic leg. Dev Biol. 1985 Oct; 111(2):383-98. View in: PubMed

  57. Ho RK, Weisblat DA. A provisional epithelium in leech embryo: cellular origins and influence on a developmental equivalence group. Dev Biol. 1987 Apr; 120(2):520-34. View in: PubMed

  58. Ho RK, Kane DA. Cell-autonomous action of zebrafish spt-1 mutation in specific mesodermal precursors. Nature. 1990 Dec 20-27; 348(6303):728-30. View in: PubMed

  59. Hatta K, Kimmel CB, Ho RK, Walker C. The cyclops mutation blocks specification of the floor plate of the zebrafish central nervous system. Nature. 1991 Mar 28; 350(6316):339-41. View in: PubMed

  60. Ho RK. Cell movements and cell fate during zebrafish gastrulation. Dev Suppl. 1992; 65-73. View in: PubMed

  61. Schulte-Merker S, Ho RK, Herrmann BG, Nüsslein-Volhard C. The protein product of the zebrafish homologue of the mouse T gene is expressed in nuclei of the germ ring and the notochord of the early embryo. Development. 1992 Dec; 116(4):1021-32. View in: PubMed