Gene Symbol: ext2
Description: exostosin glycosyltransferase 2
Alias: wu:fc14g07, exostosin-2, dackel, dak, exostoses (multiple) 2, ext2a, fc14g07
Species: zebrafish
Products:     ext2

Top Publications

  1. van Eeden F, Granato M, Schach U, Brand M, Furutani Seiki M, Haffter P, et al. Genetic analysis of fin formation in the zebrafish, Danio rerio. Development. 1996;123:255-62 pubmed
    ..Interestingly, in mutants of one of these genes, dackel (dak), pectoral fin buds form initially, but later the fin epithelium fails to expand...
  2. Holmborn K, Habicher J, Kasza Z, Eriksson A, Filipek Gorniok B, Gopal S, et al. On the roles and regulation of chondroitin sulfate and heparan sulfate in zebrafish pharyngeal cartilage morphogenesis. J Biol Chem. 2012;287:33905-16 pubmed
    ..and CS because of defective formation of the common proteoglycan linkage tetrasaccharide were analyzed along with ext2 and extl3 mutants, predicted to have defective HS polymerization...
  3. Wiweger M, Zhao Z, van Merkesteyn R, Roehl H, Hogendoorn P. HSPG-deficient zebrafish uncovers dental aspect of multiple osteochondromas. PLoS ONE. 2012;7:e29734 pubmed publisher
    ..Mutations in two enzymes that are required during heparan sulphate synthesis (EXT1 or EXT2) are known to cause MO...
  4. Norton W, Ledin J, Grandel H, Neumann C. HSPG synthesis by zebrafish Ext2 and Extl3 is required for Fgf10 signalling during limb development. Development. 2005;132:4963-73 pubmed
    ..We find that fgf10 mutants strongly resemble zebrafish ext2 and extl3 mutants, which encode glycosyltransferases required for heparan sulphate biosynthesis...
  5. Grandel H, Draper B, Schulte Merker S. dackel acts in the ectoderm of the zebrafish pectoral fin bud to maintain AER signaling. Development. 2000;127:4169-78 pubmed
    ..In this study we show that the product of the dackel (dak) gene is one of the components that acts in the epidermis of the zebrafish pectoral fin bud to maintain ..
  6. de Andrea C, Prins F, Wiweger M, Hogendoorn P. Growth plate regulation and osteochondroma formation: insights from tracing proteoglycans in zebrafish models and human cartilage. J Pathol. 2011;224:160-8 pubmed publisher
    ..and five different proteoglycan-deficient zebrafish mutants displaying one of the following skeletal phenotypes: dackel (dak/ext2), lacking heparan sulphate and identified as a model for human multiple osteochondromas; hi307 (?3gat3), ..
  7. Wiweger M, Avramut C, de Andrea C, Prins F, Koster A, Ravelli R, et al. Cartilage ultrastructure in proteoglycan-deficient zebrafish mutants brings to light new candidate genes for human skeletal disorders. J Pathol. 2011;223:531-42 pubmed publisher
    ..We analysed skeletons from five zebrafish lines with known mutations in genes involved in proteoglycan synthesis: dackel (dak/ext2), lacking heparan sulphate; hi307 (?3gat3), deficient for most GAGs; pinscher (pic/slc35b2), presenting ..
  8. Clément A, Wiweger M, von der Hardt S, Rusch M, Selleck S, Chien C, et al. Regulation of zebrafish skeletogenesis by ext2/dackel and papst1/pinscher. PLoS Genet. 2008;4:e1000136 pubmed publisher
    ..Here we show that two zebrafish mutants, dackel (dak) and pinscher (pic), have cartilage defects that strongly resemble those seen in HME patients...
  9. Lee J, von der Hardt S, Rusch M, Stringer S, Stickney H, Talbot W, et al. Axon sorting in the optic tract requires HSPG synthesis by ext2 (dackel) and extl3 (boxer). Neuron. 2004;44:947-60 pubmed
    ..In zebrafish dackel (dak) and boxer (box) mutants, some dorsal RGC axons missort in the optic tract but innervate the tectum ..

More Information


  1. Volpi S, Yamazaki Y, Brauer P, van Rooijen E, Hayashida A, Slavotinek A, et al. EXTL3 mutations cause skeletal dysplasia, immune deficiency, and developmental delay. J Exp Med. 2017;214:623-637 pubmed publisher
    ..These data identify EXTL3 mutations as a novel cause of severe immune deficiency with skeletal dysplasia and developmental delay and underline a crucial role of HS in thymopoiesis and skeletal and brain development. ..
  2. Ghiselli G, Farber S. D-glucuronyl C5-epimerase acts in dorso-ventral axis formation in zebrafish. BMC Dev Biol. 2005;5:19 pubmed
    ..In particular Glce acts during gastrulation by affecting Bmp-mediated cell specification. The results obtained further corroborate the concept that HS encodes information that affect morphogenesis during early vertebrate development. ..
  3. Baier H, Klostermann S, Trowe T, Karlstrom R, Nusslein Volhard C, Bonhoeffer F. Genetic dissection of the retinotectal projection. Development. 1996;123:415-25 pubmed
    ..The results of this screen show that a large-scale genetic approach can be applied to relatively late and circumscribed developmental processes in the vertebrate brain. ..
  4. Kawakami Y, Rodriguez Leon J, Koth C, Buscher D, Itoh T, Raya A, et al. MKP3 mediates the cellular response to FGF8 signalling in the vertebrate limb. Nat Cell Biol. 2003;5:513-9 pubmed
    ..This suggests that MKP3 has a key role in mediating the proliferative, anti-apoptotic signalling of AER-derived FGF8. ..
  5. Fischer S, Filipek Gorniok B, Ledin J. Zebrafish Ext2 is necessary for Fgf and Wnt signaling, but not for Hh signaling. BMC Dev Biol. 2011;11:53 pubmed publisher
    ..In this report we have studied Fgf, Wnt and Hedgehog (Hh) signaling in ext2 mutants, where heparan sulfate content is low...
  6. Wang F, Wolfson S, Gharib A, Sagasti A. LAR receptor tyrosine phosphatases and HSPGs guide peripheral sensory axons to the skin. Curr Biol. 2012;22:373-82 pubmed publisher
    ..HSPGs and LAR family receptors are required for sensory axon guidance to the skin. Together, our results support a model in which peripheral HSPGs are attractive ligands for LAR receptors on RB neurons. ..
  7. Poulain F, Chien C. Proteoglycan-mediated axon degeneration corrects pretarget topographic sorting errors. Neuron. 2013;78:49-56 pubmed publisher
    ..These findings uncover a function for developmental axon degeneration in ordering axonal projections and identify heparan sulfate as a key regulator of that process. ..
  8. Venero Galanternik M, Kramer K, Piotrowski T. Heparan Sulfate Proteoglycans Regulate Fgf Signaling and Cell Polarity during Collective Cell Migration. Cell Rep. 2015;: pubmed publisher
    ..Analysis of mutations in two exostosin glycosyltransferase genes (extl3 and ext2) revealed that loss of heparan sulfate (HS) chains results in a failure of collective cell migration due to ..
  9. Culverwell J, Karlstrom R. Making the connection: retinal axon guidance in the zebrafish. Semin Cell Dev Biol. 2002;13:497-506 pubmed
    ..The combination of zebrafish genetic and embryological approaches promises to greatly increase our understanding of how multiple guidance mechanisms establish the complex neural interconnectivity of the vertebrate brain. ..
  10. Wiweger M, de Andrea C, Scheepstra K, Zhao Z, Hogendoorn P. Possible effects of EXT2 on mesenchymal differentiation--lessons from the zebrafish. Orphanet J Rare Dis. 2014;9:35 pubmed publisher
    ..Zebrafish dackel (dak) mutant that carries a nonsense mutation in the ext2 gene was used in this study...
  11. Karlstrom R, Trowe T, Klostermann S, Baier H, Brand M, Crawford A, et al. Zebrafish mutations affecting retinotectal axon pathfinding. Development. 1996;123:427-38 pubmed
    ..Class IV mutant larvae (boxer, dackel, pinscher) have defects in axon sorting after the midline and retinal axons occasionally make further pathfinding ..