During vertebrate embryo development, patterning of the limbs is governed by the action of many genes. Here I have focused specifically on patterning of the digits and how they receive their identity (from thumb to little finger). I have used the chicken embryo as a model organism to study transcription factor-encoding gene expression patterns in the limb. I combined well described methods with a recently developed imaging technique, Optical Projection Tomography (OPT), to show analysis of these expression patterns in 3D. To investigate the eventual position of the descendants of cells of the early limb bud, I created a long-term fate map of the chick wing with use of the GFP-positive transgenic chicken. I have also analysed 3D images of known markers for the formation of skeletal structures in the limb and demonstrated how this could be combined with gene expression patterns and a comprehensive fate map in 3D to further understanding of limb development.
From creating a long-term fate map of the chick wing bud, I have established which areas of the early wing bud are the progenitors of each of the 3 digits of the forelimb. I have also shown how it would be possible to visualise this fate map in 3D and to combine this with 3D gene expression patterns of transcription factor-encoding genes known to be involved in digit patterning. Combining this information would show which genes are expressed in the digit progenitor cells through time, and may give an indication of the combination of genes that are required to give the digits their identity.
|Date of Award||1 Feb 2009|
|Supervisor||Cheryll Tickle (Supervisor)|
- gene expression patterns
- Limb development
- fate map