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Evidence that a late‐emerging population of trunk neural crest cells forms the plastron bones in the turtle Trachemys scripta
Author(s) -
CebraThomas Judith A.,
Betters Erin,
Yin Melinda,
Plafkin Callie,
McDow Kendra,
Gilbert Scott F.
Publication year - 2007
Publication title -
evolution and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.651
H-Index - 78
eISSN - 1525-142X
pISSN - 1520-541X
DOI - 10.1111/j.1525-142x.2007.00159.x
Subject(s) - neural crest , biology , neural tube , turtle (robot) , anatomy , neural fold , population , embryo , notochord , iliac crest , intramembranous ossification , trunk , dorsum , neural plate , embryogenesis , microbiology and biotechnology , medicine , ecology , environmental health , fishery
SUMMARY The origin of the turtle plastron is not known, but these nine bones have been homologized to the exoskeletal components of the clavicles, the interclavicular bone, and gastralia. Earlier evidence from our laboratory showed that the bone‐forming cells of the plastron were positive for HNK‐1 and PDGFRα, two markers of the skeletogenic neural crest. This study looks at the embryonic origin of these plastron‐forming cells. We show that the HNK‐1 + cells are also positive for p75 and FoxD3, confirming their neural crest identity, and that they originate from the dorsal neural tube of stage 17 turtle embryos, several days after the original wave of neural crest cells have migrated and differentiated. DiI studies show that these are migratory cells, and they can be observed in the lateral regions of the embryo and can be seen forming intramembranous bone in the ventral (plastron) regions. Before migrating ventrally, these late‐emerging neural crest cells reside for over a week in a carapacial staging area above the neural tube and vertebrae. It is speculated that this staging area is where they lose the inability to form skeletal cells.