Question

How do you predict cyclopamine treatment of zebrafish embryos will affect dorsal-ventral patterning of the neural tube? Will the fish have diminished dorsal-type neurons and expanded ventral-type neurons or will there be expanded dorsal-type neurons and diminished ventral-type neurons? (You should be able to answer this based on information given in the introduction section of the lab manual)

Answer 1

Sonic hedgehog genes (SHH) has a vast array of functions. It codes for paracrine factors which are important for the cell to cell interactions. It is responsible for the development of limb, spinal cord, tooth, hair, eye, lung. It causes ventral neural tube patterning when secreted from the notochord and floor plate of the neural tube.

Cyclopamine interferes with the SHH signaling pathway disrupting ventral neural tube patterning. So, as asked in the question, cyclopamine treatment will lead to diminished ventral type neurons and expanded dorsal type neurons.