Date of Award


Document Type

Union College Only

Degree Name

Bachelor of Science



First Advisor

Nicole Theodosiou


biology, development, skate, spiral intestine


The digestive system is crucial for the absorption of nutrients and while its function is conserved among many organisms, its form evolved to best suit an organism’s diet and environment. In cartilaginous fish like the little skate, Leucoraja erinacea, the intestines develop as a short tube with an internal fold that makes the shape of a spiral. The development of the little skate’s embryonic gut tube is directed by various genes including the ligand-receptor action of Shh and Ptch. The aim of my study was to investigate Shh function in patterning the skate digestive tract by visualizing its expression. To do this, I performed a whole mount RNA in-situ hybridization on skate embryos at stages 25 and 27. To look at the expression more closely, I sectioned and mounted stage 25 and 27 embryos which allowed us to observe key regions, such as the gut endoderm and the cloaca. I observed that Shh expression was prominent within the gut endoderm, the cloaca, the notochord, and the eye. Expression in the eye and the gut tissue was similar in fashion to that observed in the chick. The findings that Shh was expressed similarly in the skate to other animals suggests that its role during development is conserved.



Rights Statement

In Copyright - Educational Use Permitted.