ReproGen-Animal Bioscience Group, Faculty of Veterinary Science, University of Sydney, Camden, NSW, Australia; School of Science and Health, University of Western Sydney, Penrith, NSW, Australia.
Exp Dermatol. 2013 Oct;22(10):659-62. doi: 10.1111/exd.12217.
Notch pathway genes have been implicated in the commitment of mesenchymal cells to a wool follicle cell fate. Notch1 and Delta1 transcripts were quantified in fetal skin of fine-woolled (Merino) and strong-woolled (Tukidale) sheep at two time points: either preceding (d56) or during (d70) the first wave of follicle initiation. DIG-labelled probes for both transcripts were localised in the epithelium, some mesenchymal cells, and in the dermal condensates of primordia. The possibility that condensates selectively incorporated Delta1-labelled mesenchymal cells is considered. The involvement of Notch1 in condensate formation was also explored in cultured fetal skin explants and whisker papilla cells using DAPT to block Notch signalling. In its presence, follicle initiation in skin explants was reduced, and the propensity for cultured papilla cells to aggregate was abolished. Results suggest that Notch1 activation is a prerequisite for mesenchymal aggregation. It is speculated that Delta interactions contribute to condensate formation, in vivo.
Notch 通路基因参与了间充质细胞向羊毛毛囊细胞命运的决定。在绵羊胎儿皮肤的两个时间点（d56 或 d70），对细毛（美利奴）和粗毛（图基代尔）绵羊进行了 Notch1 和 Delta1 转录本的定量分析：这两个时间点都在第一次毛囊起始波之前（d56）或期间（d70）。用于两种转录本的 DIG 标记探针定位于上皮、一些间充质细胞和原始真皮浓缩物中。考虑了浓缩物是否选择性地包含标记的 Delta1 间充质细胞的可能性。还使用 DAPT 阻断 Notch 信号通路，在培养的胎儿皮肤外植体和胡须乳头细胞中探索了 Notch1 在浓缩物形成中的作用。在其存在的情况下，皮肤外植体中的毛囊起始减少，并且培养的乳头细胞聚集的倾向被消除。结果表明，Notch1 的激活是间充质聚集的先决条件。推测 Delta 相互作用有助于体内浓缩物的形成。
