Areas of Research
The Khokha laboratory is interested in the problem of embryonic patterning. A fertilized egg must activate a complex genetic program in order to form functional adult structures. The histological sections and movie of gastrulation below illustrate this early development.
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| Development of Xenopus embryo from blastula to tadpole stages. |
| Xenopus embryo undergoing gastrulation. Double click movie to play. |
| R. Keller and D. Shook |
Failure to correctly activate this genetic program leads to congenital malformations in children, a significant cause of inherited childhood diseases.
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| Image of child's heart showing severe congenital malformations, including overall defects in patterning across the left-right axis. |
We are particularly interested in cellular signals and transcriptional regulation that lead to particular fate changes that specify new tissue types during development. We are also interested in morphogenesis that provides shape to the developing embryo. We have three approaches to discover these patterning events: 1) genetic screens in Xenopus tropicalis 2) quantitative analysis of Xenopus epidermis to create a coordinated field of cells 3) human genetic studies of children with congenital malformations.
Wild-type and grinch embryos stained for epithelial cilia
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| Scanning electron microscopy image of Xenopus embronic skin epithelia revealing surface cilia |
Xenopus tropicalis Model System
We focus on Xenopus as a model system because of the power of the frog system for gain of function and experimental embryology (“cut-and-paste”developmental biology). In addition, we have pioneered X. tropicalis as an amphibian genetic system because of its diploid genome and genomic tools.
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Wild-type and grinch embryos Image: Dipankan Bhattacharya |