Genetic interactions between Ror2 and Wnt9a, Ror1 and Wnt9a and Ror2 and Ror1: Phenotypic analysis of the limb skeleton and palate in compound mutants. (20th March 2019)

• Record Type: Journal Article
• Authors: Weissenböck, Martina; Latham, Richard; Nishita, Michiru; Wolff, Lena Ingeborg; Ho, Hsin‐Yi Henry; Minami, Yasuhiro; Hartmann, Christine
• Is Part Of: Genes to cells. Volume 24:Number 4(2019)
• Page Start: 307
• Page End: 317
• Publication Date: 2019-03-20
• Subjects: chondrogenesis -- endochondral ossification -- limb skeleton -- Ror1 -- Ror2 -- secondary cleft palate -- Wnt9a; Cytogenetics -- Periodicals; Cells -- Mechanical properties -- Periodicals; Molecular genetics -- Periodicals; Genes -- Periodicals; Molecular biology -- Periodicals; Cytology -- Periodicals; Biomechanics -- Periodicals; 571.6
• DOI: 10.1111/gtc.12676
• Languages: English
• ISSNs: 1356-9597

Abstract

Abstract: Mutations in the human receptor tyrosine kinase ROR2 are associated with Robinow syndrome (RRS) and brachydactyly type B1. Amongst others, the shortened limb phenotype associated with RRS is recapitulated in Ror2 −/− mutant mice. In contrast, Ror1 −/− mutant mice are viable and show no limb phenotype. Ror1 −/− ; Ror2 −/− double mutants are embryonic lethal, whereas double mutants containing a hypomorphic Ror1 allele ( Ror1 hyp ) survive up to birth and display a more severe shortened limb phenotype. Both orphan receptors have been shown to act as possible Wnt coreceptors and to mediate the Wnt5a signal. Here, we analyzed genetic interactions between the Wnt ligand, Wnt9a, and Ror2 or Ror1, as Wnt9a has also been implicated in skeletal development. Wnt9a −/− single mutants display a mild shortening of the long bones, whereas these are severely shortened in Ror2 −/− mutants. Ror2 −/− ; Wnt9a −/− double mutants displayed even more severely shortened long bones, and intermediate phenotypes were observed in compound Ror2 ; Wnt9a mutants. Long bones were also shorter in Ror1 hyp/hyp ; Wnt9a −/− double mutants. In addition, Ror1 hyp/hyp ; Wnt9a −/− double mutants displayed a secondary palate cleft phenotype, which was not present in the respective single mutants. Interestingly, 50% of compound mutant pups heterozygous for Ror2 and homozygous mutant for Ror1 also developed a secondary palate cleft phenotype. Abstract : Alcian blue/alizarin red stained skeletal preparations of forelimbs and skulls showing the successive shortening of stylopod and zeugopodand the cleft secondary palate in the respective mutants.