title: On the roles and regulation of chondroitin sulfate and heparan sulfate in zebrafish pharyngeal cartilage morphogenesis.
abstract: The present study addresses the roles of heparan sulfate (HS) proteoglycans and chondroitin sulfate (CS) proteoglycans in the development of zebrafish pharyngeal cartilage structures. uxs1 and b3gat3 mutants, predicted to have impaired biosynthesis of both HS 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. Notably, the effects on HS and CS biosynthesis in the respective mutant strains were shown to differ from what had been hypothesized. In uxs1 and b3gat3 mutant larvae, biosynthesis of CS was shown to be virtually abolished, whereas these mutants still were capable of synthesizing 50% of the HS produced in control larvae. extl3 and ext2 mutants on the other hand were shown to synthesize reduced amounts of hypersulfated HS. Further, extl3 mutants produced higher levels of CS than control larvae, whereas morpholino-mediated suppression of csgalnact1/csgalnact2 resulted in increased HS biosynthesis. Thus, the balance of the Extl3 and Csgalnact1/Csgalnact2 proteins influences the HS/CS ratio. A characterization of the pharyngeal cartilage element morphologies in the single mutant strains, as well as in ext2;uxs1 double mutants, was conducted. A correlation between HS and CS production and phenotypes was found, such that impaired HS biosynthesis was shown to affect chondrocyte intercalation, whereas impaired CS biosynthesis inhibited formation of the extracellular matrix surrounding chondrocytes.
authors.affiliation: Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
authors.forename: Katarina
authors.initials: K
authors.lastname: Holmborn
authors.forename: Judith
authors.initials: J
authors.lastname: Habicher
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Kasza
authors.forename: Anna S
authors.initials: AS
authors.lastname: Eriksson
authors.forename: Beata
authors.initials: B
authors.lastname: Filipek-Gorniok
authors.forename: Sandeep
authors.initials: S
authors.lastname: Gopal
authors.forename: John R
authors.initials: JR
authors.lastname: Couchman
authors.forename: Per E
authors.initials: PE
authors.lastname: Ahlberg
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Wiweger
authors.forename: Dorothe
authors.initials: D
authors.lastname: Spillmann
authors.forename: Johan
authors.initials: J
authors.lastname: Kreuger
authors.forename: Johan
authors.initials: J
authors.lastname: Ledin
mesh_terms: D000483:Alleles; D000818:Animals; D002356:Cartilage / Q000378:metabolism*; D002809:Chondroitin Sulfates / Q000737:chemistry*; D003433:Crosses, Genetic; D018450:Disease Progression; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005838:Genotype; D006497:Heparan Sulfate / Q000737:chemistry*; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods; D008954:Models, Biological; D009024:Morphogenesis; D009154:Mutation; D010614:Pharynx / Q000473:pathology; D015027:Zebrafish
chemical_list: D002809:Chondroitin Sulfates; D006497:Heparan Sulfate