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Segregation of Oral from Aboral Ectoderm Precursors Is Completed at Fifth Cleavage in the Embryogenesis of Strongylocentrotus purpuratus

Cameron, R. Andrew and Fraser, Scott E. and Britten, Roy J. and Davidson, Eric H. (1990) Segregation of Oral from Aboral Ectoderm Precursors Is Completed at Fifth Cleavage in the Embryogenesis of Strongylocentrotus purpuratus. Developmental Biology, 137 (1). pp. 77-85. ISSN 0012-1606. doi:10.1016/0012-1606(90)90009-8.

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A specific set of founder cells uniquely gives rise to the oral and aboral ectoderms in the regularly developing sea urchin Strongylocentrotus purpuratus. We showed earlier that the polar No and Na (animal oral and animal aboral) blastomeres are specified by third cleavage, while the respective oral and aboral lineage contributions of the left and right NL (animal lateral) blastomeres have not yet segregated from one another at third cleavage. Here we demonstrate by iontophoretic injection of lysyl rhodamine dextran lineage tracer that segregation of oral vs aboral cell fates in the lineages of the NL blastomeres has still not occurred by fourth cleavage, but at fifth cleavage there arise from the NL sublineages founder cells whose progeny contribute exclusively to the aboral ectoderm. The sister cells of these fifth cleavage blastomeres are founder cells that contribute exclusively to oral structures. The aboral ectoderm tracts to which NL derivatives give rise occupy lateral regions of the anterior aboral ectoderm, while the oral structures deriving from the NL blastomeres are the lateral sectors of the ciliated bands. The cells of the ciliated bands do not express aboral ectoderm markers and are considered to constitute the border of the oral region. With these new findings we complete our knowledge of the origins, identities, and fates of the 11 founder cells, the progeny of which exclusively give rise to the aboral ectoderm, and of the 5 founder cells, the progeny of which exclusively produce the oral ectoderm and its derivatives.

Item Type:Article
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Cameron, R. Andrew0000-0003-3947-6041
Fraser, Scott E.0000-0002-5377-0223
Additional Information:© 1990 by Academic Press, Inc. Accepted September 11, 1989. This research was supported by NIH Grant HD-05753 (to E.H.D.) and by NSF Grant BNS-8608356 and a McKnight Scholar Award (to S.E.F.).
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McKnight FoundationUNSPECIFIED
Issue or Number:1
Record Number:CaltechAUTHORS:20121023-112006174
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Official Citation:R.Andrew Cameron, Scott E. Fraser, Roy J. Britten, Eric H. Davidson, Segregation of oral from aboral ectoderm precursors is completed at fifth cleavage in the embryogenesis of Strongylocentrotus purpuratus, Developmental Biology, Volume 137, Issue 1, January 1990, Pages 77-85, ISSN 0012-1606, 10.1016/0012-1606(90)90009-8. (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:35035
Deposited By: Ruth Sustaita
Deposited On:23 Oct 2012 18:45
Last Modified:09 Nov 2021 23:12

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