title: Pax8 and Pax2 are specifically required at different steps of Xenopus pronephros development.
abstract: The respective role of Pax2 and Pax8 in early kidney development in vertebrates is poorly understood. In this report, we have studied the roles of Pax8 and Pax2 in Xenopus pronephros development using a loss-of-function approach. Our results highlight a differential requirement of these two transcription factors for proper pronephros formation. Pax8 is necessary for the earliest steps of pronephric development and its depletion leads to a complete absence of pronephric tubule. Pax2 is required after the establishment of the tubule pronephric anlage, for the expression of several terminal differentiation markers of the pronephric tubule. Neither Pax2 nor Pax8 is essential to glomus development. We further show that Pax8 controls hnf1b, but not lhx1 and Osr2, expression in the kidney field as soon as the mid-neurula stage. Pax8 is also required for cell proliferation of pronephric precursors in the kidney field. It may exert its action through the wnt/beta-catenin pathway since activation of this pathway can rescue MoPax8 induced proliferation defect and Pax8 regulates expression of the wnt pathway components, dvl1 and sfrp3. Finally, we observed that loss of pronephros in Pax8 morphants correlates with an expanded vascular/blood gene expression domain indicating that Pax8 function is important to delimit the blood/endothelial genes expression domain in the anterior part of the dorso-lateral plate.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR7622 Developmental Biology, F-75005 Paris, France; CNRS, UMR7622 Developmental Biology, F-75005 Paris, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Buisson
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR7622 Developmental Biology, F-75005 Paris, France; CNRS, UMR7622 Developmental Biology, F-75005 Paris, France.
authors.forename: Ronan
authors.initials: R
authors.lastname: Le Bouffant
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR7622 Developmental Biology, F-75005 Paris, France; CNRS, UMR7622 Developmental Biology, F-75005 Paris, France.
authors.forename: Mélinée
authors.initials: M
authors.lastname: Futel
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR7622 Developmental Biology, F-75005 Paris, France; CNRS, UMR7622 Developmental Biology, F-75005 Paris, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Riou
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UMR7622 Developmental Biology, F-75005 Paris, France; CNRS, UMR7622 Developmental Biology, F-75005 Paris, France. Electronic address: muriel.umbhauer@upmc.fr.
authors.forename: Muriel
authors.initials: M
authors.lastname: Umbhauer
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine; D017931:DNA Primers / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D017403:In Situ Hybridization; D051762:PAX2 Transcription Factor / Q000378:metabolism*; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D060910:Pronephros / Q000196:embryology*; D060888:Real-Time Polymerase Chain Reaction; D060449:Wnt Signaling Pathway / Q000235:genetics / Q000502:physiology*; D014981:Xenopus / Q000196:embryology* / Q000235:genetics; D029867:Xenopus Proteins / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D051762:PAX2 Transcription Factor; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors; C499500:Pax8 protein, Xenopus; D029867:Xenopus Proteins; D001973:Bromodeoxyuridine
keywords: Pax2/8; Proliferation; Pronephros; Wnt; Xenopus; hnf1b