The pineal complex/epiphysis is a placode, strictly specified by the combinatorial activity of the transcription factors Flh/Noto and Dlx3

TY - JOUR

T1 - The pineal complex/epiphysis is a placode, strictly specified by the combinatorial activity of the transcription factors Flh/Noto and Dlx3

AU - Houart, Corinne

AU - Hutt, James

AU - Foucher, Isabelle

AU - Houart, Corinne

PY - 2008/7/15

Y1 - 2008/7/15

N2 - The pineal gland, or epiphysis, sits on the roof of the diencephalon and is a simple photoreceptive structure in most anamniotes that acquired aneuroendocrine role in mammals. Its structure is comparable to the primitive eye found in mollusk or ascidians. Our fate map of the anterior neural plate, in zebrafish, localized the pineal precursors in a very lateral position, coinciding with the pre-placodal territory. Genetic loss of function studies further show that the formation of the epiphysis requires Dlx3, a protein strictly expressed in placodal ectoderm. Mis-expression experiments demonstrate that the combinatorial expression of the homeodomain transcription factors Dlx3 and Flh/Noto is sufficient to confer pineal identity. Finally, observations made in otx1;otx2 double loss of function embryos reveal that pineal cell fate specification, controlled by Dlx3 and Noto, occurs during gastrulation and is negatively regulated by the Fgf signaling pathway. All together, our study uncovers the placodal nature of the pineal complex and identifies the genetic trigger of its specification during late gastrulation. Implications on evolution of the anterior neural ectoderm will be discussed.

AB - The pineal gland, or epiphysis, sits on the roof of the diencephalon and is a simple photoreceptive structure in most anamniotes that acquired aneuroendocrine role in mammals. Its structure is comparable to the primitive eye found in mollusk or ascidians. Our fate map of the anterior neural plate, in zebrafish, localized the pineal precursors in a very lateral position, coinciding with the pre-placodal territory. Genetic loss of function studies further show that the formation of the epiphysis requires Dlx3, a protein strictly expressed in placodal ectoderm. Mis-expression experiments demonstrate that the combinatorial expression of the homeodomain transcription factors Dlx3 and Flh/Noto is sufficient to confer pineal identity. Finally, observations made in otx1;otx2 double loss of function embryos reveal that pineal cell fate specification, controlled by Dlx3 and Noto, occurs during gastrulation and is negatively regulated by the Fgf signaling pathway. All together, our study uncovers the placodal nature of the pineal complex and identifies the genetic trigger of its specification during late gastrulation. Implications on evolution of the anterior neural ectoderm will be discussed.

U2 - 10.1016/j.ydbio.2008.05.491

DO - 10.1016/j.ydbio.2008.05.491

M3 - Meeting abstract

SN - 0012-1606

VL - 319

SP - 590

EP - 591

JO - Developmental Biology

JF - Developmental Biology

IS - 2

ER -