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The oral-aboral axis of a sea urchin embryo is specified by first cleavage

Cameron, R. Andrew and Fraser, Scott E. and Britten, Roy J. and Davidson, Eric H. (1989) The oral-aboral axis of a sea urchin embryo is specified by first cleavage. Development, 106 (4). pp. 641-647. ISSN 0950-1991.

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Several lines of evidence suggest that the oral-aboral axis in Strongylocentrotus purpuratus embryos is specified at or before the 8-cell stage. Were the oral-aboral axis specified independently of the first cleavage plane, then a random association of this plane with the blastomeres of the four embryo quadrants in the oral-aboral plane (viz. oral, aboral, right and left) would be expected. Lineage tracer dye injection into one blastomere at the 2-cell stage and observation of the resultant labeling patterns demonstrates instead a strongly nonrandom association. In at least ninety percent of cases, the progeny of the aboral blastomeres are associated with those of the left lateral blastomeres and the progeny of the oral blastomeres with the right lateral ones, respectively. Thus, ninety percent of the time the oral pole of the future oral-aboral axis lies 45 degrees clockwise from the first cleavage plane as viewed from the animal pole. The nonrandom association of blastomeres after labeling of the 2-cell stage implies that there is a mechanistic relation between axis specification and the positioning of the first cleavage plane.

Item Type:Article
Related URLs:
URLURL TypeDescription
Cameron, R. Andrew0000-0003-3947-6041
Fraser, Scott E.0000-0002-5377-0223
Additional Information:© 1989 Company of Biologists Ltd. Accepted 19 April 1989. Research was supported by NIH Grant HD-05753 (to E.H.D.) and by NSF Grant BNS8608356 and a McKnight Scholar Award (to S.E.F.). The manuscript improved through the helpful criticism of our colleagues, Drs B. Hough-Evans, E. Rothenberg and R. Whittaker.
Funding AgencyGrant Number
McKnight FoundationUNSPECIFIED
Subject Keywords:iontophoretic injection; Strongylocentrotus purpuratus; cell lineage
Issue or Number:4
Record Number:CaltechAUTHORS:20120510-091723549
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:31404
Deposited On:10 May 2012 17:58
Last Modified:03 Oct 2019 03:51

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