"The Strongylocentrotus purpuratus hnf6 (Sphnf6) gene encodes a new member of the ONECUT family of transcription factors. The expression of hnf6 in the developing embryo is triphasic, and loss-of-function analysis shows that the Hnf6 protein is a transcription factor that has multiple distinct roles in sea urchin development."

"hnf6 is expressed maternally, and before gastrulation its transcripts are distributed globally."

"Early in development, its expression is required for the activation of PMC differentiation genes such as sm50, pm27, and msp130, but not for the activation of any known PMC regulatory genes, for example, alx, ets1, pmar1, or tbrain."

"Micromere transplantation experiments show that the gene is not involved in early micromere signaling."

"Early hnf6 expression is also required for expression of the mesodermal regulator gatac."

"The second known role of hnf6 is its participation after gastrulation in the oral ectoderm gene regulatory network (GRN), in which its expression is essential for the maintenance of the state of oral ectoderm specification."

"The third role is in the neurogenic ciliated band, which is foreshadowed exactly by a trapezoidal band of hnf6 expression at the border of the oral ectoderm and where it continues to be expressed through the end of embryogenesis. Neither oral ectoderm regulatory functions nor ciliated band formation occur normally in the absence of hnf6 expression."

"The sea urchin transcription factor SpHNF6 is an early activator of differentiation genes in skeletogenic lineages and regulatory genes in the oral ectoderm."

"The vertebrate and the echinoderm hnf6 and onecut genes belong to the novel ONECUT homeo domain class of transcription factors."

"As is observed in sea urchin, by the end of gastrulation, the expression of AmHNF6 is distinctly localized to the ciliary bands."

"The isolated sea urchin gene, named SpOnecut, encodes a protein of 483 amino acids with one cut domain and a homeodomain."

"In the sea urchin embryo, expression is first detected in the emerging ciliary band at the late blastula stage. During the gastrula stage, expression is limited to the ciliary band."

"This is the first gene known that exclusively marks the ciliary band and therein the apical organ in a pluteus larva"

"these differentiation genes require as drivers products of all of the now familiar components of the skeletogenic regulatory state ( alx1 , ets1 , tbr , tel , erg , hex , foxb , dri ) and in addition a factor that is at this stage ubiquitously present, Hnf6 ( 42 )."

"Indeed one such factor is included in the micromere lineage GRN ( hnf6 ) and its ancillary “booster” function is illustrative."

"These are the early oral ectoderm and later ciliated band genes hnf6 and otxβ1/2"

"there appear to be four early genetic components producing the initial zygotic transcriptional regulatory state in the specification of the oral ectoderm: the nodal independent hnf6, and otxβ1/2 genes; the nodal dependant gsc repressor, and the nodal dependant foxg activator."

"knock-down of dri (Amore et al., 2003), of hnf6 (Otim et al., 2004), or of gsc (Angerer et al., 2001), all cause expression of spec1 to spread around the whole ectoderm"

"From early gastrula stage onwards, genes initially expressed thoughout the oral ectoderm resolve to this trapezoidal band, i.e, the hnf6 (Otim et al., 2004), otxβ1/2 (Yuh et al., 2002), and foxg (Tu et al., 2006) genes"