title: In vivo imaging and characterization of actin microridges.
abstract: Actin microridges form labyrinth like patterns on superficial epithelial cells across animal species. This highly organized assembly has been implicated in mucus retention and in the mechanical structure of mucosal surfaces, however the mechanisms that regulate actin microridges remain largely unknown. Here we characterize the composition and dynamics of actin microridges on the surface of zebrafish larvae using live imaging. Microridges contain phospho-tyrosine, cortactin and VASP, but not focal adhesion kinase. Time-lapse imaging reveals dynamic changes in the length and branching of microridges in intact animals. Transient perturbation of the microridge pattern occurs before cell division with rapid re-assembly during and after cytokinesis. Microridge assembly is maintained with constitutive activation of Rho or inhibition of myosin II activity. However, expression of dominant negative RhoA or Rac alters microridge organization, with an increase in distance between microridges. Latrunculin A treatment and photoconversion experiments suggest that the F-actin filaments are actively treadmilling in microridges. Accordingly, inhibition of Arp2/3 or PI3K signaling impairs microridge structure and length. Taken together, actin microridges in zebrafish represent a tractable in vivo model to probe pattern formation and dissect Arp2/3-mediated actin dynamics in vivo.
authors: Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States of America; Program in Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706, United States of America.
authors: Pui-ying
authors: PY
authors: Lam
authors: Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, United States of America.
authors: Steve
authors: S
authors: Mangos
authors: Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States of America.
authors: Julie M
authors: JM
authors: Green
authors: Department of Internal Medicine, Rush University Medical Center, Chicago, IL 60612, United States of America.
authors: Jochen
authors: J
authors: Reiser
authors: Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States of America; Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53706, United States of America.
authors: Anna
authors: A
authors: Huttenlocher
mesh_terms: D000199:Actins / Q000378:metabolism* / Q000648:ultrastructure*; D000818:Animals; D048749:Cytokinesis; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure; D057054:Molecular Imaging; D059008:Time-Lapse Imaging; D015027:Zebrafish
chemical_list: D000199:Actins
references: Trends Cell Biol. 1997 Sep;7(9):342-7
references: 17708978
references: Histol Histopathol. 2006 Mar;21(3):219-26
references: 16372243
references: Nature. 2010 May 20;465(7296):373-7
references: 20485438
references: Philos Trans R Soc Lond B Biol Sci. 2000 Sep 29;355(1401):1171-6
references: 11079392
references: J Cell Sci. 2012 Dec 15;125(Pt 24):5984-97
references: 23038780
references: Genetics. 2006 Oct;174(2):639-49
references: 16959904
references: Biol Cell. 2000 Oct;92(7):477-94
references: 11229600
references: J Morphol. 2009 Jun;270(6):714-28
references: 19123241
references: PLoS One. 2011;6(5):e20654
references: 21655190
references: Biotechniques. 2007 Sep;43(3):313-4, 316, 318-20 passim
references: 17907574
references: Dev Cell. 2013 Dec 23;27(6):648-55
references: 24316147
references: Anat Rec. 1976 Jun;185(2):253-7
references: 1275311
references: Annu Rev Cell Dev Biol. 1996;12:463-518
references: 8970735
references: J Cell Sci. 2013 Nov 1;126(Pt 21):5005-17
references: 23986484
references: Nature. 1992 Nov 12;360(6400):179-83
references: 1436096
references: Invest Ophthalmol Vis Sci. 2006 Oct;47(10):4341-8
references: 17003424
references: Hum Reprod. 1998 Nov;13(11):3211-9
references: 9853883
references: Bioarchitecture. 2014 Mar-Apr;4(2):39-46
references: 24844289
references: J Cell Sci. 2005 Jan 15;118(Pt 2):369-79
references: 15632107
references: Nature. 2010 Nov 25;468(7323):580-4
references: 21107430
references: Dis Model Mech. 2011 Nov;4(6):777-85
references: 21816950
references: Science. 2010 Sep 24;329(5999):1616-20
references: 20929839
references: Nat Methods. 2008 Jul;5(7):605-7
references: 18536722
references: Anat Rec. 1991 Jun;230(2):164-8
references: 1714256
references: Cell Motil Cytoskeleton. 2007 Nov;64(11):822-32
references: 17685442
references: Nat Commun. 2010;1:66
references: 20842190
references: Bull Math Biol. 1990;52(1-2):153-97; discussion 119-52
references: 2185858
references: FEBS Lett. 2005 Mar 28;579(9):2001-8
references: 15792810
references: J Ultrastruct Res. 1979 Dec;69(3):316-30
references: 159961
references: Clin Exp Optom. 2012 Mar;95(2):140-5
references: 22251199
references: J Cell Biol. 1996 Nov;135(4):1097-107
references: 8922389
references: Int J Biochem Cell Biol. 1998 Mar;30(3):307-11
references: 9611773
references: Structure. 1996 Jun 15;4(6):647-51
references: 8805551
references: Curr Biol. 2009 Aug 25;19(16):1389-95
references: 19631537
references: Trends Cell Biol. 2005 Dec;15(12):651-8
references: 16243528
references: Aquat Toxicol. 2000 Apr 1;48(4):517-527
references: 10794834
references: J Cell Biol. 2012 Oct 15;199(2):225-34
references: 23045550
references: Vet Ophthalmol. 2015 May;18(3):214-20
references: 24373492
references: Dev Cell. 2011 Oct 18;21(4):735-45
references: 22014524
references: Dev Cell. 2010 Feb 16;18(2):226-36
references: 20159593
references: PLoS One. 2013;8(3):e57051
references: 23505418
references: Science. 2003 Dec 5;302(5651):1704-9
references: 14657486