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Updated: Nov 18, 2025
Shifting Zebrafish Lethal Skeletal Mutant Penetrance by Progeny Testing
Published on: September 1, 2017
Latent developmental potential to form limb-like skeletal structures in zebrafish
M Brent Hawkins1, Katrin Henke2, Matthew P Harris2
1Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Department of Orthopedic Research, Boston Children's Hospital, Boston, MA 02115, USA; Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138, USA.
Zebrafish fin mutations reveal new genes controlling bone development. These genetic changes activate a latent limb-like pattern, adding extra bones to fins and offering insights into vertebrate evolution.
Area of Science:
- Evolutionary biology
- Developmental genetics
- Comparative anatomy
Background:
- Appendage evolution, particularly the fin-to-limb transition, is crucial for vertebrate locomotion diversity.
- Skeletal element addition along the proximal-distal axis drives major evolutionary transformations.
Purpose of the Study:
- Identify genetic regulators of appendage patterning in zebrafish.
- Investigate the role of novel genes in fin skeletal development and homology with limbs.
Main Methods:
- Zebrafish mutagenesis screens to identify mutants with supernumerary pectoral fin bones.
- Analysis of gene function (vav2, waslb) and genetic interactions (Hox11, hoxa11b).
- Comparative analysis of mutant phenotypes in zebrafish and mice.
Main Results:
- Zebrafish mutants with supernumerary pectoral fin long bones were identified.
- Activating mutations in previously unknown genes, vav2 and waslb, were found to cause this phenotype.
- The vav2/waslb pathway is essential for appendage development and interacts with Hox genes, suggesting developmental homology with vertebrate forelimbs.
Conclusions:
- A latent limb-like patterning ability exists in fins, activated by specific genetic perturbations.
- The vav2/waslb pathway represents a conserved mechanism regulating appendage patterning across vertebrates.
- Understanding these pathways sheds light on the genetic basis of the fin-to-limb transition.
