Graduation Date
Spring 2023
Document Type
Thesis
Program
Master of Science degree with a major in Biology
Committee Chair Name
Allison Bronson
Committee Chair Affiliation
HSU Faculty or Staff
Second Committee Member Name
John Reiss
Second Committee Member Affiliation
HSU Faculty or Staff
Third Committee Member Name
Karen Kiemnec-Tyburczy
Third Committee Member Affiliation
HSU Faculty or Staff
Fourth Committee Member Name
Ethan Gahtan
Subject Categories
Biology
Abstract
Neural crest cells (NCCs) and mesodermal somites independently produce embryonic mesenchyme as a precursor to the chondrocytes and osteocytes of the vertebrate skeleton. In mammals and teleosts, NCCs only contribute to the dermal cranial skeleton, while the mesodermal somites and lateral plate mesoderm form the entire dermal and endochondral postcranial skeleton. In sharks, NCCs contribute to both the cranial and trunk integumentary skeleton. This suggests that contribution of the trunk neural crest mesenchyme to the integumentary skeleton was an ancestral condition for all vertebrates that was lost over evolutionary time in the osteichthyan lineage, but the evolutionary timing of this loss is unclear. This study documents trunk neural crest cell delamination and migration from the neural crest and investigates the developmental origin of the dermal bony scutes in White Sturgeon (Acipenser transmontanus). I find that putative trunk neural crest cells emigrate from the neural crest before neural tube closure. This is the first described evidence among vertebrates of this timing of trunk neural crest cell emigration. I also provide evidence that the bony scutes of White Sturgeon may at least partially develop from the neural crest. This suggests that contribution of trunk neural crest ectomesenchyme to the exoskeleton was a vertebrate ancestral condition that was preserved in early-diverging lineages of bony fishes, and convergently lost in teleosts and tetrapods.
Citation Style
Harvard
Recommended Citation
Tew, Melody, "Neural crest cell migration and developmental origin of bony scutes in White Sturgeon (Acipenser transmontanus)" (2023). Cal Poly Humboldt theses and projects. 657.
https://digitalcommons.humboldt.edu/etd/657