title: Embryonic expression of engrailed in sea urchins.
abstract: Neural patterning genes that are expressed along the anterior-posterior axis of deuterostomes are expressed late in larval development in echinoderms and are thought to function in establishing the highly-derived, adult body plan. We have used genomic resources to clone an engrailed gene (SpEn) from Strongylocentrotus purpuratus, and with this we have developed an antibody specific for SpEn. SpEn is expressed late in embryogenesis in the developing larval nervous system. At the prism stage, a small number of neuroblasts in the oral ectoderm on the edge of the larval mouth begin expressing SpEn. The cells are in bilaterally symmetric positions. The expression of SpEn precedes the expression of the neural markers, synaptotagmin and serotonin in the SpEn immunoreactive cells. The SpEn cells are located on the margin of the domain of cells expressing SpNK2.1, but they do not have nuclear SpNK2.1. Expression of engrailed in a pair of bilateral neural structures in early development appears to be a shared feature of bilaterians.
authors.affiliation: Department of Biology, University of Victoria, 3800 Finnerty Road, Victoria, BC, Canada. rburke@uvic.ca
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yaguchi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Nakajima
authors.forename: Diana
authors.initials: D
authors.lastname: Wang
authors.forename: Robert D
authors.initials: RD
authors.lastname: Burke
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D005260:Female; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D051381:Rats; D011916:Rats, Inbred F344; D012617:Sea Urchins / Q000196:embryology*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*
chemical_list: D017931:DNA Primers; D018398:Homeodomain Proteins; D014157:Transcription Factors; C106185:engrailed homeobox proteins