SpHnf6, a transcription factor that executes multiple functions in sea urchin embryogenesis

• Published in: Developmental biology Vol. 273; no. 2; pp. 226 - 243
• Main Authors: Otim, Ochan, Amore, Gabriele, Minokawa, Takuya, McClay, David R., Davidson, Eric H.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-09-2004
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Cell Differentiation; Cloning, Molecular; DNA, Complementary - genetics; Gene Expression Regulation, Developmental; Gene Targeting; hnf6; Marine; Mesoderm - cytology; Models, Biological; Molecular Sequence Data; Morpholino antisense oligonucleotide; Oligonucleotides, Antisense - genetics; ONECUT; Oral ectoderm; Phenotype; PMC; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sea urchin embryo; Sea Urchins - embryology; Sea Urchins - genetics; Sea Urchins - metabolism; Space life sciences; Transcription factor; Transcription Factors - genetics; Transcription Factors - metabolism; Morpholino antisense oligonucleotide; Sea urchin embryo; hnf6; ONECUT; PMC; Transcription factor; Oral ectoderm; Non-programmatic
• ISSN: 0012-1606; 1095-564X
• DOI: 10.1016/j.ydbio.2004.05.033

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.