Abstract:
The Foxi3 transcription factor, expressed in the neural plate border at the end of gastrulation, is necessary for the formation of posterior placodes and is thus important for ectodermal patterning. We have created two knock-in mouse lines expressing GFP or a tamoxifen-inducible Cre recombinase to show that Foxi3 is one of the earliest genes to label the border between the neural tube and epidermis, and that Foxi3-expressing neural plate border progenitors contribute primarily to cranial placodes and epidermis from the onset of expression, but not to the neural crest or neural tube lineages. By simultaneously knocking out Foxi3 in neural plate border cells and following their fates, we show that neural plate border cells lacking Foxi3 contribute to all four lineages of the ectoderm - placodes, epidermis, crest and neural tube. We contrast Foxi3 with another neural plate border transcription factor, Zic5, the progenitors of which initially contribute broadly to all germ layers until gastrulation and gradually become restricted to the neural crest lineage and dorsal neural tube cells. Our study demonstrates that Foxi3 uniquely acts early at the neural plate border to restrict progenitors to a placodal and epidermal fate.
摘要:
FOxi3转录因子在胃泌膜结束时在神经板边界中表达,对于后胎盘的形成是必需的,因此对于外胚层模式很重要。我们创建了两个表达GFP或他莫昔芬诱导型Cre重组酶的敲入小鼠系,以表明FOxi3是最早标记神经管和表皮之间边界的基因之一。并且从表达开始,Foxi3表达的神经板边界祖细胞主要有助于颅骨胎盘和表皮,但不是神经脊或神经管谱系。通过同时敲除神经板边缘细胞中的Foxi3并跟随它们的命运,我们发现缺乏Foxi3的神经板边缘细胞有助于外胚层-胎盘的所有四个谱系,表皮,波峰,和神经管。我们将Foxi3与另一个神经板边界转录因子进行对比,Zic5,其祖细胞最初对所有胚层都有广泛的贡献,直到胃泌成,并逐渐限制到神经c谱系和背侧神经管细胞。我们的研究表明,FOxi3在神经板边界的早期独特作用,将祖细胞限制在胎盘和表皮命运。