The Evolution of HoxD-11 Expression in the Bird Wing
Author Information
Author(s): Vargas Alexander O., Kohlsdorf Tiana, Fallon John F., VandenBrooks John, Wagner Günter P.
Primary Institution: Department of Ecology and Evolutionary Biology, Yale University
Hypothesis
A homeotic frame shift of digital identity occurred in the evolution of the bird wing.
Conclusion
The study found that late-phase HoxD-11 expression is absent only in digit 1 of alligators, supporting the hypothesis of a shift in digit morphology and gene expression in the evolution of the bird wing.
Supporting Evidence
- HoxD-11 expression in alligator is consistent with the hypothesis that both digit morphology as well as HoxD-11 expression are shifted towards posterior in the bird wing.
- The anterior limit of late-phase HoxD-11 expression does not extend into the biphalangeal digit 1.
- Late-phase expression of HoxD-11 is asymmetric in the pectoral fins of the basal bony fish, indicating an ancient marker of positional identity.
Takeaway
This study looked at how a specific gene behaves in alligators and found that it helps explain how bird wings developed differently from their ancestors.
Methodology
The researchers cloned a fragment of the HoxD-11 gene from alligator embryos and used in-situ hybridization to study its expression.
Digital Object Identifier (DOI)
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