... development Spec genes ectoderm differentiation animal cap During early embryogenesis, a cleaving embryo produces blastomeres that adopt vastly different developmental fates. Single blastomeres or groups of blastomeres divide to produce clones of cells that constitute embryonic territories giving...

...Craig R. Tomlinson; Mark T. Kozlowski; William H. Klein The Spec gene family of Strongylocentrotus purpuratus is expressed exclusively in aboral ectoderm cells during embryogenesis. To investigate the regulation of Spec gene activity, the region around the Spec1 transcriptional initiation site...