Question

Vertebrates have a gene called Pax6, and this gene codes for a protein that functions as a transcription factor. Where-ever Pax6 protein is produced in young embryos, an eye develops. a. Where would the Pax6 gene be normally expressed in this embryo? b. If one could cause the Pax6 gene to be expressed on the stomach of an embryo, what do you suppose would happen? c. Pax 6 protein is a transcription factor. What does that mean in terms of protein function? d. Eye development is complicated, and it includes lots of cell  cell signaling (inductions). How is it that a transcription factor can result in cell to cell signaling?

Answer 1

a) The Pax6 gene is a key factor in the development of lens and normally expressed in the facial ectoderm in vertebrates.

b) During embryonic development, the Pax6 gene is also expressed on the stomach, it may play a role in the development of endocrine pancreas.

c) Pax6 protein is expressed as a transcription factor because during embryonic development because it activate genes invoved in the development of eyes, brain, pancreas and spinal cord.

d) The ability of one group of cells to affect the activity of another group of cells is called induction. During eye development the Pax6 is very essential for lens induction in vertebrates and invertebrates. It serves as a regulator in the differentiation and proliferation in oculogenesis. The multifunctional nature of Pax6 direct the molecular signaling in the formation of central nervous system (CNS). The Wnt/ß-catenin pathway plays important roles in neuroepithelial cells during embryonic development. It controls radial glial proliferation and neurogenesis through transcriptional activation of Pax6.