QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Klapper, R. Articles by Janning, W. Search for Related Content PubMed PubMed Citation Articles by Klapper, R. Articles by Janning, W.

A new approach reveals syncytia within the visceral musculature of Drosophila melanogaster

Institut für Allgemeine Zoologie und Genetik der Westfälischen Wilhelms-Universität, Schlossplatz 5, 48149 Münster, Germany

View larger version (39K): [in a new window]   Fig. 1. The GAL4/UAS transplantation system. (A) Single cells are transplanted from UAS-GFP donors into da-GAL4 recipients at the blastoderm stage. After differentiation, GFP expression (green) is expected only in those syncytia that contain both donor- and recipient-derived nuclei. (B) To detect all descendants of the transplanted cell, the UAS-GFP donor embryos were labelled with the fluorescent dye RITC-dextran (red) at the preblastoderm stage before the transplantation. In the differentiated da-GAL4 recipients all mononuclear tissues, such as the fat body, generated by the descendants of the transplanted cell are solely labelled by RITC-dextran (red). Syncytia containing donor- and recipient-derived nuclei, like somatic muscles, exhibit an additional GFP expression (yellow indicates fluorescence superimposition of GFP and RITC-dextran).

View larger version (27K): [in a new window]   Fig. 2. The GAL4/UAS transplantation system exclusively labels syncytia. A clone in a stage 17 embryo that overlaps fat body and somatic musculature. All descendants of the transplanted cell are labelled red by the cell-lineage marker RITC-dextran (A), whereas syncytia containing both donor- and recipient-derived nuclei express GFP (B). The superimposition (C) reveals that the syncytia marker GFP is not expressed in the mononuclear fat body (asterisk). This tissue is solely labelled by the cell-lineage marker. Most somatic muscles are double labelled and therefore represent syncytia consisting of clonally non-related nuclei. The muscle indicated by the arrowhead is labelled only by the cell-lineage marker, indicating that this syncytium consists exclusively of donor-derived nuclei.

View larger version (99K): [in a new window]   Fig. 3. The GAL4/UAS transplantation system highlights syncytia in third-instar larvae. (A) The expression of GFP, here used as a cell-lineage marker, demonstrates that the descendants of a single transplanted cell gave rise to two cells of the fat body (insert) and also contributed to a larval somatic muscle. (B) Only the muscle fraction of the clone expresses the syncytia marker ß-galactosidase as revealed by X-Gal staining.

View larger version (33K): [in a new window]   Fig. 4. GFP expression labels syncytia within the longitudinal visceral musculature at different stages of development. (A) Stage 17 embryo, (B) third-instar larva, (C) dissected midgut of an adult fly.

View larger version (76K): [in a new window]   Fig. 5. The visceral musculature of the hindgut consists of syncytia throughout development. (A) First signs of GFP expression within the circular musculature of the hindgut (arrowheads) become visible in stage 15 embryos. (B) In some cases, labelling that overlapped visceral musculature of the hindgut (arrowhead) and larval somatic muscles (arrow) was detected. In the dissected hindgut of a third-instar larva (C), the reticulated structure of the individual muscles covering only one half of the gut tube becomes distinct. In adult flies (D), the circular muscles of the hindgut have lost their meshed structure and surround the gut tube as small bands, either entirely (arrowhead) or over about half its circumference (arrows).