Dissection of Zebrafish Craniofacial Tissues upon Staining with Alcian Blue.

Zebrafish, given its optical transparency, is an excellent vertebrate model to study the mechanisms by which craniofacial cartilages form in the embryo. Craniofacial cartilages can be broadly classified into two groups, the neurocranium and the viscerocranium, which in turn can be subdivided into numerous cartilage groups necessary for supporting the brain and constituting the feeding and respiratory apparatus, among others. This protocol will first describe a simple and established staining procedure in zebrafish to visualize these cartilage groups, followed by a methodology to dissect and separate the neuro and the viscerocranium. From these dissections, simple shape and size metrics can be easily obtained, and in this protocol, this is demonstrated for the palate, which is part of the anterior neurocranium, a tissue often affected in most craniofacial disorders in humans. The protocol can be replicated in a straightforward manner even in resource-limited settings, thus providing a valuable educational tool for undergraduate students to get introduced to craniofacial morphology.