Ellis L C, Smith A M, Alvarez I S, Schoenwolf G C
Department of Anatomy, University of Utah School of Medicine, Salt Lake City 84132.
Anat Rec. 1993 Apr;235(4):591-603. doi: 10.1002/ar.1092350412.
The goal of our laboratory research is to elucidate the mechanisms underlying gastrulation and neurulation, using the avian embryo as a model system. In previous studies, we used two approaches to map the morphogenetic movements involved in these processes: (1) we constructed quail/chick transplantation chimeras in which grafted quail cells could be identified within chick host embryos by the presence of nucleolar-associated heterochromatin, and (2) we microinjected exogenous cell markers. However, it would be advantageous to be able to detect endogenous markers to demarcate various subsets of cells within the unmanipulated embryo. To elucidate such a series of natural markers, we have used monoclonal antibodies to identify epitopes found on subsets of ectodermal, mesodermal, and endodermal cells. Antibodies were made by immunizing mice against either homogenized ectoderm (i.e., prospective neural plate and surface ectoderm) or primitive streak, which had been microdissected from stage 3 chick embryos. Additionally, we screened a panel of antibodies made against soluble protein obtained from isolates of cell nuclei from late embryonic chick brain. Here, we describe the labeling patterns of three monoclonal antibodies, called MAb-GL1, GL2, and GL3 (GL, germ layer), during avian gastrulation and neurulation. Our results show that labeling early avian embryos with monoclonal antibodies can reveal previously undetected distributions of cells bearing shared epitopes, providing new labels for subsets of cells in each of the three primary germ layers.
我们实验室研究的目标是，以鸡胚作为模型系统，阐明原肠胚形成和神经胚形成的潜在机制。在之前的研究中，我们采用了两种方法来描绘这些过程中涉及的形态发生运动：（1）构建鹌鹑/鸡移植嵌合体，其中通过核仁相关异染色质的存在，可以在鸡宿主胚胎中识别移植的鹌鹑细胞；（2）显微注射外源性细胞标记物。然而，能够检测内源性标记物以划分未受操作胚胎内的各种细胞亚群将是有利的。为了阐明这样一系列天然标记物，我们使用单克隆抗体来识别在外胚层、中胚层和内胚层细胞亚群上发现的表位。通过用来自3期鸡胚显微解剖的匀质外胚层（即预期神经板和表面外胚层）或原条免疫小鼠来制备抗体。此外，我们筛选了一组针对从晚期鸡胚脑细胞核分离物中获得的可溶性蛋白制备的抗体。在此，我们描述了三种单克隆抗体（称为MAb-GL1、GL2和GL3，GL，胚层）在鸡原肠胚形成和神经胚形成过程中的标记模式。我们的结果表明，用单克隆抗体标记早期鸡胚可以揭示携带共享表位的细胞以前未被检测到的分布，为三个主要胚层中每个胚层的细胞亚群提供新的标记。
