In the series of morphogenetic events that are required for Drosophila development, some of the most dramatic are those that involve the coordinated movement of the germband and amnioserosa, two epithelia that remain contiguous through the first thirteen hours of morphogenesis until the amnioserosaâs death. The importance of the amnioserosa in ensuring the germbandâs proper shape and position has been established, but its exact role as a signaling source and force generator and the balance between amnioserosal and germband forces are not fully understood. Pursuing this question from the germband side of the balance, a new angle-measurement method has yielded information from germband cell edges about the tensions and stresses acting during germband retraction. These results show that the amnioserosa pulls on the germband to produce cell and segment elongation, while the germband cell-edge tensions are polarized to resist elongation, acting in the same direction that they do during the preceding stage of germband extension. The degree of force anisotropy varies in different germband segments, indicating that a more detailed analysis of the entire germband is required to understand the amnioserosa-germband force balance. Other avenues of research support vertical germband polarization and the general picture of the amnioserosa as an essential player in morphogenesis, exerting forces on the germband that are instrumental in proper development.
| Identifer | oai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-03272017-112322 |
| Date | 05 April 2017 |
| Creators | Bennett, Monica Elaine |
| Contributors | Prof. John Wikswo, Ph.D., Prof. Andrea Page-McCaw, Ph.D., Prof. Erin Rericha, Ph.D., Prof. M. Shane Hutson, Ph.D. |
| Publisher | VANDERBILT |
| Source Sets | Vanderbilt University Theses |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.vanderbilt.edu/available/etd-03272017-112322/ |
| Rights | restrictone, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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