Please use this identifier to cite or link to this item:
http://hdl.handle.net/11375/22476
Title: | The Midline Glial Cell Lineage in the Post Embryonic Fruit Fly Drosophila melanogaster |
Authors: | Perz, Michael Jonathan |
Advisor: | Jacobs, J. Roger |
Department: | Biology |
Keywords: | ultrastructure, glia, drosophila melanogaster |
Publication Date: | Dec-1994 |
Abstract: | This study investigated the position, ultrastructure and life history of glia in the midline of the Drosophila melanogaster Central Nervous System (CNS) by using enhancer traps (AA142, X81, argoswll, pointed1277) and reporter constructs (EEl, slilacZ 1.0, slilacZ 4.5) as glial-specific markers. Previous work has established that glia are necessary for proper formation and morphogenesis of longitudinal and commissural axon tracts, and axon ensheathment (Jacobs, 1993; Klambt et al., 1991; Jacobs and Goodman, 1989). By the end of embryogenesis there are three midline glial (MG) cells remaining in each segment (Sonnenfeld and jacobs, in press) which this study verifies. In the third instar larval MG cells proliferate to 24 cells per segment as followed with the E. coli lacZ expressing pointed1277 strain. These E. coli lacZ expressing pointed1277 MG cells begin dividing 57 hours after hatching as seen with 5 -bromodeoxyuridine and hydroxyurea treatment. Some MG genes cease midline expression before MG proliferation (seen with EEl, X81), others (seen with AA142) continue to be expressed until the beginning of MG proliferation. Only the argoswll, slilacZ 1.0, slilacZ 4.5, and pointed1277 expression strains continue E. coli lacZ expression to the end of the larval stages. In the first larval stage a few perineuropilar glia begin to express the E. coli lacZ gene and increase to 400 cells per CNS in the third ins tar as seen in the pointed1277 marker strain. pointed1277 EM micrographs show that E. coli lacZ labeled cells have a glial-like ultrastructure. There - was no co-localization of the E. coli lacZ expression in pointed12 77 and an anti-RK2 (repo) antibody in third instar larvae. In pointed1277 pupae the MG cell E. coli lacZ expression stops after 48- 72 hours and the prerineuropilar signal stops after 24 hours. In newly hatched pointed1277 adults perineuropilar E. coli lacZ expression is present with a cluster of 12 cells in the center of the neuropil. To summarize, after embryogenesis, in the pointed1277 marker strain, the MG cells begin dividing after 57 hours and the E. coli lacZ gene expression ends after the second day of the pupal stage. In the first instar, perineuropilar glia begin to label for the E. coli lacZ product and this expression ends by one day into the pupal stage, with re-appearance in the adult CNS. |
URI: | http://hdl.handle.net/11375/22476 |
Appears in Collections: | Digitized Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Perz_Michael_J_1994_Dec_Masters.pdf | 4.95 MB | Adobe PDF | View/Open |
Items in MacSphere are protected by copyright, with all rights reserved, unless otherwise indicated.