Title | Did the first chordates organize without the organizer? |
Publication Type | Journal Article |
Year of Publication | 2005 |
Authors | Kourakis MJ, Smith WC |
Journal | Trends Genet |
Volume | 21 |
Issue | 9 |
Pagination | 506-10 |
Date Published | 2005 Sep |
ISSN | 0168-9525 |
Keywords | Animals, Biological Evolution, Body Patterning, Chordata, Chordata, Nonvertebrate, Embryonic Development, Organizers, Embryonic, Xenopus laevis |
Abstract | Models of vertebrate development frequently portray the organizer as acting on a largely unpatterned embryo to induce major components of the body plan, such as the neural plate and somites. Recent experiments examining the molecular and genetic basis of major inductive events of vertebrate embryogenesis force a re-examination of this view. These newer observations, along with a proposed revised fate map for the frog Xenopus laevis, suggest a possible reconciliation between the seemingly disparate mechanisms present in the ontogeny of the common chordate body plan of vertebrate and invertebrate chordates. Here, we review data from vertebrates and from an ascidian urochordate and propose that the organizer was not present at the base of the chordate lineage, but could have been a later innovation in the lineage leading to vertebrates, where its role was more permissive than instructive. |
DOI | 10.1016/j.tig.2005.07.002 |
Alternate Journal | Trends Genet. |
PubMed ID | 16023252 |
Grant List | HD041434 / HD / NICHD NIH HHS / United States HD38701 / HD / NICHD NIH HHS / United States |