title: Sox18 and Sox7 play redundant roles in vascular development.
abstract: Mutations in SOX18 cause the human hypotrichosis-lymphedema-telangiectasia (HLT) syndrome. Their murine counterparts are the spontaneous ragged mutants, showing combined defects in hair follicle, blood vessel, and lymphatic vessel development. Mice null for Sox18 display only mild coat defects, suggesting a dominant-negative effect of Sox18/ragged mutations and functional redundancy between Sox18 and other Sox-F proteins. We addressed this point in zebrafish. The zebrafish homologs of Sox18 and of Sox7 are expressed in angioblasts and in the endothelial component of nascent blood vessels in embryos. Knockdown of either gene, using moderate doses of specific morpholinos, had minimal effects on vessels. In contrast, simultaneous knockdown of both genes resulted in multiple fusions between the major axial vessels. With combined use of transgenic lines and molecular markers, we could show that endothelial cells are specified, but fail to acquire a correct arteriovenous identity. Venous endothelial cell differentiation was more severely affected than arterial. Thus, sox7 and sox18 play redundant but collectively essential roles in the establishment of proper arteriovenous identity in zebrafish. Our data suggest that a defect in arteriovenous identity could be responsible for the formation of telangiectases in patients with HLT.
authors: Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Via Celoria 26, Milan, Italy.
authors: Solei
authors: S
authors: Cermenati
authors: Silvia
authors: S
authors: Moleri
authors: Simona
authors: S
authors: Cimbro
authors: Paola
authors: P
authors: Corti
authors: Luca
authors: L
authors: Del Giacco
authors: Roberta
authors: R
authors: Amodeo
authors: Elisabetta
authors: E
authors: Dejana
authors: Peter
authors: P
authors: Koopman
authors: Franco
authors: F
authors: Cotelli
authors: Monica
authors: M
authors: Beltrame
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D015415:Biomarkers / Q000378:metabolism; D001775:Blood Circulation; D001808:Blood Vessels / Q000002:abnormalities / Q000196:embryology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000002:abnormalities; D042783:Endothelial Cells / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity; D055760:SOXF Transcription Factors; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D004268:DNA-Binding Proteins; D055760:SOXF Transcription Factors; C526282:Sox18 protein, zebrafish; C526281:Sox7 protein, zebrafish; D029961:Zebrafish Proteins