Origins of radial symmetry identified in an echinoderm during adult development and the inferred axes of ancestral bilateral symmetry.
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ABSTRACT:
SUBMITTER: Morris VB
PROVIDER: S-EPMC2176165 | biostudies-other | 2007 Jun
REPOSITORIES: biostudies-other
Publications
Origins of radial symmetry identified in an echinoderm during adult development and the inferred axes of ancestral bilateral symmetry.
Proceedings. Biological sciences 20070601 1617
How the radial body plan of echinoderms is related to the bilateral body plan of their deuterostome relatives, the hemichordates and the chordates, has been a long-standing problem. Now, using direct development in a sea urchin, I show that the first radially arranged structures, the five primary podia, form from a dorsal and a ventral hydrocoele at the oral end of the archenteron. There is a bilateral plane of symmetry through the podia, the mouth, the archenteron and the blastopore. This adult ...[more]
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