Senior Honors Projects, 2010-2019

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Date of Graduation

Spring 2014

Document Type


Degree Name

Bachelor of Science (BS)


Department of Biology


Carol Hurney

Susan Halsell

Patrice M. Ludwig


Tails are common among most vertebrates. The embryonic tails of most vertebrates grow into adulthood while other vertebrates absorb them. Interestingly, some species of salamanders have the ability to add axial segments to their tails post-embryonically. In the salamander, Hemidactylium scutatum, postembryonic growth of the tail is due to the development of new caudal vertebrae, as well as the growth of pre-existing segments. The mechanisms that drive the postembryonic segmentation in salamanders are relatively unexplored and may offer insights on the molecular nature of tail development in vertebrates. I found evidence that larval and adult tail growth could be utilizing the same mechanisms for tail segmentation that are used in embryonic tail development by comparing the expression of Wnt8 and My5 in the developing tails of H. scutatum embryos, larvae, and adults. Specifically, the expression of Wnt8 in the growing tails suggests that both larval and adult H. scutatum continue to segment through the use of a molecular oscillating clock and/or a tail organizer, which induces the tail to undergo somitogenesis and, with the aid of Myf5, develop skeletal muscle in the tail.



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