In a Xenopus animal cap assay Vegetal cells are placed next

In a Xenopus animal cap assay, Vegetal cells are placed next to cells from the top of the Animal pole. Consider this scenario for the following question:

If we inject a Xnr inhibitor into the vegetal cells, what happens? Why?

Solution

Xnr is a responsible for the Nodal formation. When Xnr inhibitor added to them it effect the Ectoderm and endoderm formation. Induction of vegetal cell stopped beacuse of Xnr inhibitor.In normal the Xnr gene express from dorsal to ventral region.Xnr expression release the protein which specify the mesoderm.Region with Xnr gene expression becomes the lateral mesoderm. Xnr gene transcribed proteins will activate the goosecoid gene, and the inhibitor of Xnr gene prevents this action.

Animal cap cell becomes epidermis and vegetal cell helps in formation of gutlike tissue. So inhibition of this Xnr gene cause deffect in nodal region formation.