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 Wendling, O. Articles by Mark, M. Search for Related Content PubMed PubMed Citation Articles by Wendling, O. Articles by Mark, M.

Roles of retinoic acid receptors in early embryonic morphogenesis and hindbrain patterning

Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS/INSERM/ULP/Collège de France, B.P. 163, 67404 ILLKIRCH Cedex, C.U. de STRASBOURG, France

View larger version (90K): [in a new window]   Fig. 1. Morphology of E9.5 wild type (A), A/A (B) and A/Aß+/-/A (C-E) mutants. Single arrows point to the open rhombencephalon and the double arrow to abnormal folding of the neural tube. A, heart atrium; B1-B3, pharyngeal (branchial) arches 1-3; L, limb; O and O*, orthotopic and ectopic otic vesicles; OT, heart outflow tract; R2-R5, rhombomeres 2 to 5; S, somites; V, heart ventricle. Brackets delineate the opening of the ventral body wall.

View larger version (110K): [in a new window]   Fig. 2. Frontal histological sections at comparable levels of the hindbrain (A,B) and of the midgut (C,D) of wild type (A,C) and A/A mutants (B,D) at E9.5. B3, branchial arch 3; H, heart; MG, midgut; O orthotopic otocyst; O*, ectopic otocyst; P, pharynx; R, rhombencephalon; U, umbilical vein. The arrow points to the persistent opening of the gut. Scale bar: 35 µm (A,B); 60 µm (C,D).

View larger version (85K): [in a new window]   Fig. 3. Abnormal hindbrain specification in A/A embryos. Distribution of Krox20 (A,D); Hoxb1 (B,E) and kreisler (C,F) transcripts in E8.5 wild-type (A-C) and A/A (D-F) embryos. Dorsal views. 1S, first somite; OS, otic sulcus; pR3-pR5, pro-rhombomere 3-5; pR5/6, pro-rhombomeres 5 and 6; PS, preotic sulcus. The bracket in D encompasses the expression domain of Krox20.

View larger version (49K): [in a new window]   Fig. 4. Enlargement of the postotic rhombencephalon in E8+24hours BMS493-treated embryos. Distribution of Krox20 (A,B), Hoxb1 (C,D), kreisler (E,F) and Hoxd4 (G,H) transcripts on dorsal views of cultured embryos. The arrows mark the anterior limit of Hoxd4 transcripts in the spinal cord. R5, rhombomere 5; SC, spinal cord.

View larger version (78K): [in a new window]   Fig. 5. RA-signaling defines the kreisler expression domain. E8.0 embryos cultured for 3 hours in the presence of ethanol (control, A) and BMS493 (B,C). The arrows point to the otic sulcus.

View larger version (92K): [in a new window]   Fig. 6. Hindbrain patterning defects in E7.0 embryos cultured for 48 hours in the presence of BMS493 as indicated. Distribution of Krox20 (A-C), Hoxb1 (D,E), kreisler (F-H), EphA2 (I,J) transcripts on lateral (A-C,F-J) and dorsal (D,E) views of cultured embryos. pR3-pR5, pro-rhombomeres 3 to 5; SC, spinal cord.

View larger version (13K): [in a new window]   Fig. 7. Schematic representation of the morphological and molecular hindbrain patterning defects observed in various type of embryos displaying altered retinoid signalling. (A-C) Segmental expression of Krox20, Hoxb1, kreisler and Hoxd4 at E9.5. (A) Wild-type embryos; (B) RAR/RARß double-null mutant embryos (Dupé et al., 1999); (C) cultured embryos treated with the pan-RAR antagonist BMS493 at E8.0. (D-G) Segmental expression of Krox20, Hoxb1 and kreisler at E8.5. (D) Wild-type embryos; (E) RALDH2-null mutant embryos (Niederreither et al., 2000); (F) RAR/RAR double-null mutant embryos; (G) cultured embryos treated with BMS493 at E7.0. PS, preotic sulcus; OS, otic sulcus; R2-R7, rhombomeres 2 to 7; pR2-pR6, pro-rhombomeres 2 to 6; SC, spinal cord. The unbroken lines represent homogeneous expression of the gene, and the broken lines a patchy expression.