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

First published online 17 November 2004
doi: 10.1242/dev.01530

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 Related articles in Development 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 Tripodi, M. Articles by Studer, M. Search for Related Content PubMed PubMed Citation Articles by Tripodi, M. Articles by Studer, M. Social Bookmarking                         What's this?

The COUP-TF nuclear receptors regulate cell migration in the mammalian basal forebrain

Marco Tripodi^*, Alessandro Filosa^*, Maria Armentano and Michèle Studer

TIGEM (Telethon Institute of Genetics and Medicine), Via P. Castellino 111, 80131 Napoli, Italy

View larger version (87K): [in a new window]   Fig. 1. COUP-TFs are expressed in migrating cells. Adjacent coronal sections of an E13.5 mouse brain at a medio-caudal level immunostained with anti-COUP-TFI (A) and COUP-TFII antibodies (A'). The asterisks in A and A' indicate expression in the interganglionic region (the `MLGE'). The insets show an enlargement of this region after double labelling of COUP-TFs (COUP-TFI mRNA/COUP-TFII antibody in A; COUP-TFI antibody/COUP-TFII mRNA in A'). The arrow in A indicates the expression boundary of COUP-TFI at the level of the medial cortex, whereas in the same region COUP-TFII is expressed in the putative cortical hem region (ch in A'). An arrow in A' indicates expression in the marginal zone of the ncx, and the arrowheads show expression at the cortico-striatal boundary and in the intermediate zone of the ncx. (B-B''') Two different enlargements of the regions indicated in A and A'. Most COUP-TF-positive cells show a polarized soma (arrows in B-B'''), indicative of migrating cells. (C-C') Expression of COUP-TFs in the POa region. Note that COUP-TFI is mostly restricted in the ventricular zone and in two streams of migrating cells, as indicated by the arrows. High expression of COUP-TFII is mainly localized in the mantle zone and in a dorsally migrating stream (arrow in C'). ch, cortical hem region; cp, choroid plexus; LGE, lateral ganglionic eminence; MGE, medial ganglionic eminence; mz, mantle zone; ncx, neocortex; pcx, piriform cortex; POa, pre-optic area; VZ, ventricular zone.

View larger version (130K): [in a new window]   Fig. 2. COUP-TFI is expressed in GABAergic interneurons, while COUP-TFII is expressed in Cajal-Retzius cells. Double immunofluorescence of COUP-TFs (green) and cell-type-specific markers (red) in coronal sections of E13.5 (A-G) and E15.5 (H,I) mouse brains. COUP-TFI (A,B), but not COUP-TFII (D,E), co-labels with calbindin in the MZ of the ncx (A,D) and of the pcx (B,E). COUP-TFII (F,G,H), but not COUP-TFI (C,I) co-labels with reelin in the MZ of the neocortex (C,F) and in the caudomedial cortical wall (G-I). The inset in G is a schematic diagram of the section, and indicates the position of panels (G-I). The arrows indicate double-positive cells. Note that in H, all the cells are double positive, while in I none of the cells are double positive. MZ, marginal zone; ncx, neocortex; pcx, piriform cortex.

View larger version (113K): [in a new window]   Fig. 3. COUP-TFI-positive cells in the MZ of the cortex originate from the basal telencephalon. (A) A grafting experiment performed at E13.5, in which dorsally migrating cells are analysed. The box delineates the area shown in C-H. (B) Example of an MLGE transplant that shows GFP-positive cells migrating dorsally into the ctx, laterally into the pcx, and ventrally into the POa/hypo. (C-H) Double immunofluorescence for GFP (green) and COUP-TFs (red) shows that GFP-positive cells originating from the graft are double positive for COUP-TFI in the MZ (arrowheads in C-E) and in the ventricle-oriented cells deriving from the MZ (arrows in C-E). Arrows in insets show labelling of cells in the intermediate zone (IZ). (F-H) Double immunofluorescence of GFP (green) and COUP-TFII (red) shows no co-localization of these two proteins. ctx, cortex; MZ, marginal zone; pcx, piriform cortex; POa/hypo, pre-opic area/anterior hypothalamus.

View larger version (111K): [in a new window]   Fig. 4. Dorsal-to-ventral migration within the basal telencephalon. (A) A grafting experiment performed at E13.5, in which ventrally migrating cells are analysed. The box delineates the area shown in C-E''. (B) Example of a graft in which GFP-positive cells have reached the POa. Arrows in C show co-localization of COUP-TFI (red) with GFP (green), whereas no co-labelling with COUP-TFII (red) has been identified (D) within the migratory cells. (E-E'') Arrows in (E'') indicate that migrating cells are neurons by double labelling of GFP (green) with Tuj1 (red). (E'') is a merge of panels (E) and (E'). (F) Double immunofluorescence of COUP-TFI (green) and GABA (red) shows that some COUP-TFI-positive cells (arrows) are GABAergic in the ventral migratory stream. (G) By electroporation of a GFP-expressing construct into the MLGE region, GFP-positive cells migrate ventrally, and these cells express COUP-TFI (arrows in H). Similarly, by inserting a DiI crystal into the MLGE region, fluorescent cells are detected ventrally, in the POa/hypothalamic region (I). These cells co-express COUP-TFI (J). The arrow indicates a leading process. Note that the diffuse red signal in J is the result of the DiI signal after fixation.

View larger version (121K): [in a new window]   Fig. 5. Cells originating from the caudal ganglionic eminence can migrate ventrally. (A) Summary of the type of graft and the results obtained after 60 hours of incubation. (B) A caudal ganglionic eminence (CGE) transplant shows GFP-positive cells migrating ventrally in two streams: a medial stream and a lateral stream. The arrows indicate that a few cells have reached the anterior hypothalamus. (C-F) Double immunofluorescence of GFP (green) and COUP-TFI (C,D) or COUP-TFII (red); E,F) on adjacent sections of the graft shown in B. Note that all GFP-positive cells have a leading process oriented ventrally (arrows), but that only COUP-TFI is double positive for GFP (insets in C,D). ant hypo, anterior hypothalamus; LS, lateral stream; MS, medial stream.

View larger version (73K): [in a new window]   Fig. 6. COUP-TFI modulates dorsal and ventral migration in brain slices. (A) Summary of the type of experiments performed on E13.5 mouse brain slices. On one side, a GFP-expressing vector is injected as a control, while on the contralateral side an injection of a COUP-TFI-IRES-GFP expressing vector shows an increased rate of migrating cells. (B) The average value of the GFP/GFPtot ratio (black columns) or the GFP-COUP-TFI/GFPtot ratio (white columns) of all of the injected slices, calculated independently in the cortex or ventrally in the POa (see also Materials and methods). Bars indicate standard errors of the mean. In the COUP-TFI injected side, 72±4% of the GFP-positive cells migrate into the cortex, versus 24±4% of the GFP-positive cells in the control side. For the POa ectopic expression of COUP-TFI, 46±3% of the GFP-positive cells were induced to migrate, versus 17±3% in the control situation. Significant P-values are indicated (for the cortex P=0.0008, for the POa P=0.004). Example of a control (C) and a COUP-TFI overexpressing (D) brain slice after 60 hours of incubation. The vectors were focally injected into the MLGE region. Note that in the control situation (C), a few cells were found in the cortex (C'), while the majority remain compacted in the injection point. (D) After injection of high levels of COUP-TFI into the MLGE region, the GFP-positive cells are more dispersed (arrowheads) around the injection point, and a more pronounced contingent of cells migrates in the dorsal and ventral directions. MZ, marginal zone; Cx, cortex.

View larger version (83K): [in a new window]   Fig. 7. COUP-TFII regulates migration into the intermediate zone of the neocortex. (A) Summary of the type of experiments performed on E13.5 mouse brain slices. The respective vectors are depicted to the left of each part of the diagram. (B) The average values of the GFP/GFPtot ratio (black column) and the COUP-TFII-GFP/GFPtot ratio (white column) in the cortex of all of the injected slices. Bars indicate standard errors of the mean. In the COUP-TFII injected side, 60±4% of the injected cells migrate into the cortex, versus 25±5% of the GFP-positive cells in the control side. Examples of control (C) and COUP-TFII mis-expressing (D) brain slices in which the vectors have been injected into the Str. (C) Arrows indicate GFP-positive cells in the MZ, whereas arrowheads indicate the IZ migratory stream. (D) Arrowheads indicate a higher amount of GFP-positive migrating cells in the IZ of the neocortex, whereas no cells are seen in the MZ (asterisk). Dotted line shows the putative boundary between neocortex and striatum. All the cells external to the dotted line have been counted as cells located in the cortex. IZ, intermediate zone; MZ, marginal zone; Str, striatum.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

Twitter