The Broad Role of Nkx3.2 in the Development of the Zebrafish Axial Skeleton

• The transcription factor Nkx3.2 (Bapx1) is an important chondrocyte maturation inhibitor. Previous Nkx3.2 knock-down and overexpression studies in non-mammalian gnathostomes have focused on its role in primary jaw joint development, while little is known about the function of this gene in broader skeletal development. We generated CRISPR/Cas9 knockout of nkx3.2 in zebrafish and applied a range of techniques to characterize skeletal phenotypes at developmental stages from larva to adult, revealing fusions in bones of the occiput, the loss or deformation of bony elements derived from basiventral cartilages of the vertebrae, and an increased length of the proximal radials of the dorsal and anal fins. These phenotypes are reminiscent of Nkx3.2 knockout phenotypes in mammals, suggesting that the function of this gene in axial skeletal development is ancestral to osteichthyans. Our results highlight the broad role of nkx3.2 in zebrafish skeletal development and its context-specific functions in different skeletal elements.

Subject headings

NATURVETENSKAP  -- Biologi -- Utvecklingsbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Developmental Biology (hsv//eng)

Keyword

nkx3.2

bapx1

zebrafish

jaw joint

axial skeleton

occipital

basiventral cartilage

fin radials

CRISPR/Cas9 mutant

Biology with specialization in Evolutionary Organismal Biology

Biologi med inriktning mot evolutionär organismbiologi

Publication and Content Type

vet (subject category)

ovr (subject category)