Wikimedia Commons

File:Schemes depicting territory homologies between the dogfish and vertebrate model organisms.jpg

Original file ‎(1,027 × 1,175 pixels, file size: 315 KB, MIME type: image/jpeg)

Captions

Captions

Add a one-line explanation of what this file represents

Summary edit

Description

Figure 7. Schemes depicting territory homologies between the dogfish and vertebrate model organisms.

A. Regionalisation of the site of mesoderm internalisation : comparison between the dogfish, xenopus and chick. Axial (red), paraxial (purple) and lateral (light blue) presumptive mesoderm components show the same relative location along the dogfish posterior arms, xenopus marginal ring and chick primitive streak. An additional minor mesoderm cell population, proposed to contribute to extraembryonic blood islands, is also internalised at lateral and anterior levels of the dogfish blastoderm margin (dark blue). We suggest that this cell population may be evolutionary related both to the presumptive ventral mesoderm, located to the ventral part of the marginal ring in xenopus, and extraembryonic mesoderm, internalised at the posterior part of the primitive streak in amniotes. A, anterior; P, posterior; V, ventral; D, dorsal (refer to the nomenclature paragraph in the Materials and methods section for the use of these terms in the manuscript).

B. Similarities in the relative organisation of extraembryonic and embryonic territories between the dogfish and amniotes at blastula and early gastrula stages. Columns 1, 2, 3 and 4 show proposed territory homologies between the dogfish and the vertebrate model organisms at early blastula (1), late blastula (2), early gastrula (3) and mid-gastrula (4) stages respectively. A single blastula stage is shown in xenopus and zebrafish, since the conservation of the temporal sequence of gene expression inductions is less clear with these species. At early blastula stages, the dogfish blastoderm shows a partitioning into two territories, which on the basis of Bmp4, Nodal and Otx expressions, can be related to dorsal (orange) and ventral (yellow) territories of early zebrafish or xenopus embryos, as well as to inner cell mass (orange) and trophectoderm (yellow)-derived territories of the mouse egg cylinder. In the dogfish, this early polarity can be aligned with the later antero-posterior axis of the embryo proper (schematised on the right of the figure). At late blastula stages (column 2), homologous dorsal territories (shown in gray) expressing Gsc, Lim1 and Otx are induced at the level of the dogfish posterior margin, chick Koller's sickle, mouse embryonic visceral endoderm. Comparisons between the three species suggest that a posterior expansion of the blastula Bmp4 positive extraembryonic territory has taken place in amniotes (columns 1, 2, 3). Whether a remnant of the site of posterior fusion hypothesized by this evolutionary model (dotted line in columns 2, 3, 4) may persist in amniotes remains an opened question. The early organizer (red) is induced concomitantly with the anterior displacement of the hypoblast/AVE homologs (green, column 3). The site of mesoderm internalisation (column 4) is depicted as in A. Prox., proximal; Dist., distal.
Date 2007-04-118
Source https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0000374 Evolution of Axis Specification Mechanisms in Jawed Vertebrates: Insights from a Chondrichthyan. PLoS ONE 2(4): e374. https://doi.org/10.1371/journal.pone.0000374
Author Coolen M, Sauka-Spengler T, Nicolle D, Le-Mentec C, Lallemand Y, Silva CD, et al.

Copyright: © 2007 Coolen et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Licensing edit

w:en:Creative Commons
attribution
This file is licensed under the Creative Commons Attribution 4.0 International license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
This file, which was originally posted to an external website, has not yet been reviewed by an administrator or reviewer to confirm that the above license is valid. See Category:License review needed for further instructions.

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current20:51, 11 April 2024Thumbnail for version as of 20:51, 11 April 20241,027 × 1,175 (315 KB)Rasbak (talk | contribs){{information |description=Figure 7. Schemes depicting territory homologies between the dogfish and vertebrate model organisms. A. Regionalisation of the site of mesoderm internalisation : comparison between the dogfish, xenopus and chick. Axial (red), paraxial (purple) and lateral (light blue) presumptive mesoderm components show the same relative location along the dogfish posterior arms, xenopus marginal ring and chick primitive streak. An additional minor mesoderm cell population, propos...

You cannot overwrite this file.

There are no pages that use this file.

File usage on other wikis

The following other wikis use this file:

Retrieved from "https://commons.wikimedia.org/w/index.php?title=File:Schemes_depicting_territory_homologies_between_the_dogfish_and_vertebrate_model_organisms.jpg&oldid=867553315"