Skip Navigation

American Zoologist 1983 23(3):639-654; doi:10.1093/icb/23.3.639
© 1983 by The Society for Integrative and Comparative Biology
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by GORBMAN, A.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Early Development of the Hagfish Pituitary Gland: Evidence for the Endodermal Origin of the Adenohypophysis1

AUBREY GORBMAN
Department of Zoology, University of Washington Seattle, Washington 98195

The adenohypophysis in early head fold stage hagfish embryos is at first a distinct differentiated thickening of the archenteric roof where it contacts the developing infundibular portion of the brain. This portion of the archenteron eventually becomes the dorsal epithelium of the nasopharyngeal duct. The later development of the adenohypophysis involves formation of multiple acinar outgrowths of the dorsal nasopharyngeal epithelium which together form a layered mass of follicular tissue adjacent to the neurohypophysis. This mode of origin of the adenohypophysis by endodermal polyinvagination and delamination differs from all other vertebrates, including the lampreys. The pertinence of this new information for considerations of monophyletic versus diphyletic evolutionary origins of the modern cyclostome groups is pointed out. The unusual development of the hagfish adenohypophysis presents some new and unanticipated puzzles within the general question of pituitary evolution.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.