Robinow syndrome DVL1 variants disrupt morphogenesis and appendage formation in a Drosophila disease model

Gamze Akarsu1,2, Katja R MacCharles1,2, Kenneth Kin Lam Wong1,2

  • 1Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.

Abstract

Insights

Robinow syndrome variants in Dishevelled 1 (DVL1) disrupt epithelial development by altering cell death and basement membranes. This research provides insights into the developmental consequences of these genetic mutations.

Area of Science:

  • Developmental Biology
  • Genetics
  • Molecular Biology

Background:

  • Robinow syndrome is a rare developmental disorder linked to Wnt signaling pathway gene variants.
  • Previous studies demonstrated that Dishevelled 1 (DVL1) variants disrupt Wnt signaling balance in model organisms.

Purpose of the Study:

  • To investigate the morphological consequences of expressing a prototype DVL1 pathogenic variant (DVL11519ΔT).
  • To elucidate the role of cell death, basement membrane integrity, and signaling pathways in DVL1 variant-induced developmental defects.

Main Methods:

  • Expression of DVL11519ΔT in Drosophila models.
  • Analysis of epithelial imaginal disc development, cell proliferation, and apoptosis.
  • Assessment of basement membrane components, matrix metalloproteinase activity (Mmp1), JNK signaling, collagen IV (Viking) abundance, and Bone Morphogenetic Protein (BMP) pathway activity (dad-lacZ).

Main Results:

  • DVL11519ΔT expression disrupted leg and wing epithelial imaginal disc development, increasing cell death without affecting proliferation.
  • Altered epithelial morphology was not solely due to caspase-dependent cell death.
  • Observed were changes in basement membrane components, ectopic Mmp1 expression, tissue distortion dependent on JNK signaling, abnormal collagen IV abundance, and elevated BMP signaling.

Conclusions:

  • DVL1 variants implicated in autosomal dominant Robinow syndrome cause significant developmental defects.
  • These findings enhance understanding of the complex developmental consequences of DVL1 variants in Robinow syndrome.

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