Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
Abstract
Hox genes are noted for their roles in specifying axial identity in bilateral forms. In the radial echinoderms, the axis whose identity Hox genes might specify remains unclear. From the expression of Hox genes in the development of the sea urchin Holopneustes purpurescens reported here and that reported previously, we clarify the axis that might be specified by Hox genes in echinoderms. The expression of HpHox11/13 here is described at three developmental stages. The expression is around the rim of the blastopore in gastrulae, in the archenteron wall and adjacent mesoderm in early vestibula larvae, and in a patch of mesoderm close to the archenteron wall in later vestibula larvae. The retained expression of HpHox11/13 in the patch of mesoderm in the later vestibula larvae is, we suggest, indicative of a posterior or an aboral growth zone. The expression of HpHox3 at the echinoid-rudiment stage, in contrast, is in oral mesoderm beneath the epineural folds, concentrated in sites where the first three adult spines form. With the expression of HpHox5 and HpHox11/13 reported previously, the expressions here support the role of Hox genes in specifying oral-aboral identity in echinoderms. How such specification and a posterior growth zone add support to a concept of the structural homology between echinoderms and chordates is discussed.
Arenas-Mena,
Spatial expression of Hox cluster genes in the ontogeny of a sea urchin.
2000, Pubmed,
Echinobase
Arenas-Mena,
Spatial expression of Hox cluster genes in the ontogeny of a sea urchin.
2000,
Pubmed
,
Echinobase
Arenas-Mena,
Expression of the Hox gene complex in the indirect development of a sea urchin.
1998,
Pubmed
,
Echinobase
Cameron,
Unusual gene order and organization of the sea urchin hox cluster.
2006,
Pubmed
,
Echinobase
Cisternas,
Expression of Hox4 during development of the pentamerous juvenile sea star, Parvulastra exigua.
2009,
Pubmed
,
Echinobase
de Rosa,
Caudal and even-skipped in the annelid Platynereis dumerilii and the ancestry of posterior growth.
2005,
Pubmed
Duboc,
Left-right asymmetry in the sea urchin embryo is regulated by nodal signaling on the right side.
2005,
Pubmed
,
Echinobase
Duboc,
Nodal and BMP2/4 signaling organizes the oral-aboral axis of the sea urchin embryo.
2004,
Pubmed
,
Echinobase
Duboc,
A conserved role for the nodal signaling pathway in the establishment of dorso-ventral and left-right axes in deuterostomes.
2008,
Pubmed
,
Echinobase
Ferrier,
Ciona intestinalis ParaHox genes: evolution of Hox/ParaHox cluster integrity, developmental mode, and temporal colinearity.
2002,
Pubmed
Garcia-Fernàndez,
Hox, ParaHox, ProtoHox: facts and guesses.
2005,
Pubmed
Hara,
Expression patterns of Hox genes in larvae of the sea lily Metacrinus rotundus.
2006,
Pubmed
,
Echinobase
Kmita,
Organizing axes in time and space; 25 years of colinear tinkering.
2003,
Pubmed
Lewis,
A gene complex controlling segmentation in Drosophila.
1978,
Pubmed
Long,
Evolution of echinoderms may not have required modification of the ancestral deuterostome HOX gene cluster: first report of PG4 and PG5 Hox orthologues in echinoderms.
2003,
Pubmed
,
Echinobase
Mallo,
Hox genes and regional patterning of the vertebrate body plan.
2010,
Pubmed
McGinnis,
Homeobox genes and axial patterning.
1992,
Pubmed
Minsuk,
Axial patterning of the pentaradial adult echinoderm body plan.
2009,
Pubmed
,
Echinobase
Mooi,
Arrays in rays: terminal addition in echinoderms and its correlation with gene expression.
2005,
Pubmed
,
Echinobase
Morris,
Origins of radial symmetry identified in an echinoderm during adult development and the inferred axes of ancestral bilateral symmetry.
2007,
Pubmed
,
Echinobase
Morris,
cDNA hox sequences 3' of the homeobox isolated from the sea urchin Holopneustes purpurescens are definitive for sea urchin Hox orthologues.
2002,
Pubmed
,
Echinobase
Morris,
Early development of coelomic structures in an echinoderm larva and a similarity with coelomic structures in a chordate embryo.
2012,
Pubmed
,
Echinobase
Morris,
On the sites of secondary podia formation in a juvenile echinoid: growth of the body types in echinoderms.
2009,
Pubmed
,
Echinobase
Morris,
Coelomogenesis during the abbreviated development of the echinoid Heliocidaris erythrogramma and the developmental origin of the echinoderm pentameral body plan.
2011,
Pubmed
,
Echinobase
Morris,
Involvement of two Hox genes and Otx in echinoderm body-plan morphogenesis in the sea urchin Holopneustes purpurescens.
2005,
Pubmed
,
Echinobase
Morris,
Expression of an Otx gene in the adult rudiment and the developing central nervous system in the vestibula larva of the sea urchin Holopneustes purpurescens.
2004,
Pubmed
,
Echinobase
Peter,
A gene regulatory network controlling the embryonic specification of endoderm.
2011,
Pubmed
,
Echinobase
Peterson,
The A/P axis in echinoderm ontogeny and evolution: evidence from fossils and molecules.
2000,
Pubmed
,
Echinobase
Schier,
Nodal signaling in vertebrate development.
2003,
Pubmed
Smith,
The larval stages of the sea urchin, Strongylocentrotus purpuratus.
2008,
Pubmed
,
Echinobase
Smith,
Nodal expression and heterochrony in the evolution of dorsal-ventral and left-right axes formation in the direct-developing sea urchin Heliocidaris erythrogramma.
2008,
Pubmed
,
Echinobase