Grim M, Halata Z
Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic.
Anat Embryol (Berl). 2000 Nov;202(5):401-10. doi: 10.1007/s004290000121.
We have investigated the developmental origin and ultrastructure of avian Merkel cells by electron microscopy and chick/quail transplantation experiments. On embryonic day 3, chick leg primordia were homotopically grafted onto Japanese quail host embryo. Fourteen days later, quail cells that had migrated into grafted chick legs were identified according to the masses of heterochromatin associated with the nucleolus that are characteristic for quail. Both in chick and quail, Merkel cells are usually located in the dermis just below the epidermis. They are placed between nerve terminals either individually or in small groups wrapped in sheaths that are formed by glial cell processes. Occasionally, some Merkel cells appear in nerve fascicles and within Herbst corpuscles. Merkel cells, as well as glial cells, in grafted chicken legs were of quail origin. This finding provides evidence against the epidermal origin of avian Merkel cells and indicates that Merkel cells are derived from neural crest cells that colonise, together with glial cells and melanocytes, the developing limb primordium.
我们通过电子显微镜和鸡/鹌鹑移植实验研究了鸟类默克尔细胞的发育起源和超微结构。在胚胎第3天，将鸡腿部原基同位移植到日本鹌鹑宿主胚胎上。14天后，根据与鹌鹑特有的核仁相关的异染色质团块，识别出迁移到移植鸡腿部的鹌鹑细胞。在鸡和鹌鹑中，默克尔细胞通常位于表皮下方的真皮中。它们单个或成小群地置于神经末梢之间，被神经胶质细胞突起形成的鞘包裹着。偶尔，一些默克尔细胞出现在神经束和赫伯斯特小体中。移植鸡腿部的默克尔细胞以及神经胶质细胞均来源于鹌鹑。这一发现为鸟类默克尔细胞并非起源于表皮提供了证据，并表明默克尔细胞源自神经嵴细胞，这些神经嵴细胞与神经胶质细胞和黑素细胞一起定植于发育中的肢体原基。
