Mesoderm Induction Experiment

Set up:

About 1,000 frog embryos at the early cleavage stage

GFP injection

Label one half of the embryos with GFP, the other half will be unlabeled

Procedure: 

After one half of the embryos have been labeled with GFP, let all of the embryos grow for 6 hrs until blastula stage is reached (multicellular).  The non-injected embryos’ animal pole would be removed and cultured alone to serve as a control.   The recombination will be of the GFP vegetal mass (endoderm) and the non-labeled animal cap (ectoderm).  The mesodermal tissue will be discarded.  The embryos will then develop for two days until the neurulation stage is reached.

Results:

At the neurulation stage, the non-recombinant embryos’ animal pole would give rise to the surface ectoderm, which is expected.  The recombinant embryos would have a GFP labeled epidermis AND GFP labeled notochord.

Conclusions:

Because both the ectoderm and the mesoderm are labeled with GFP, it suggests that the animal pole cells that would usually become ectoderm derivatives were induced to also become mesoderm derivatives.  The GFP labeled ectoderm and notochord indicates that the vegetal endoderm is what induces the ectoderm.