THE NOTCH GENE-PRODUCT IS A GLYCOPROTEIN EXPRESSED ON THE CELL-SURFACE OF BOTH EPIDERMAL AND NEURONAL PRECURSOR CELLS DURING DROSOPHILA DEVELOPMENT
THE NOTCH GENE-PRODUCT IS A GLYCOPROTEIN EXPRESSED ON THE CELL-SURFACE OF BOTH EPIDERMAL AND NEURONAL PRECURSOR CELLS DURING DROSOPHILA DEVELOPMENT
复制标题
DOI：
10.1083/jcb.109.5.2427
复制
发表时间：
1989-11-01
影响因子：
7.8
通讯作者：
ARTAVANISTSAKONAS, S
中科院分区：
文献类型：
--
作者：
JOHANSEN, KM;FEHON, RG;ARTAVANISTSAKONAS, S
黑腹果蝇（Drosophila melanogaster）的Notch基因座是少数合子作用的“神经源性”基因之一，参与胚胎发生过程中神经与表皮谱系的正确分离以及其他胚胎后发育事件。我们已经生成了针对Notch蛋白三个区域的抗体探针，以研究Notch蛋白的表达并开始对该蛋白进行生化表征。与基于DNA序列数据的预测一致，这里我们收集的证据表明Notch编码一个大的、糖基化的表面蛋白，其表观分子质量为300 kD:(a)所有三种抗体在Western blots上检测到Notch作为一个高分子质量，主要是全长产物；(b)免疫电镜观察Notch蛋白在细胞膜上的定位；(c)扁豆凝集素柱结合表明该蛋白是糖基化的，表明其表面蛋白的性质。总的来说，Notch蛋白的分布与先前通过原位杂交确定的Notch转录物的分布一致。Notch在更广泛的组织类型中表达，而不是在神经原性突变中被破坏的组织类型中表达，这是由抗体定位确定的。除了极细胞外，胚层的早期标记似乎普遍存在，但随着发育的进行，一些独特的特征出现了：在胚带层中，神经母细胞分层发生，可见更强的染色，发育中的胚胎神经系统显示明显的轴突染色。在三龄幼虫中，Notch在象盘和中枢神经系统中表达。基于这些结果，Notch如何控制神经母细胞命运选择的某些模型被淘汰。我们讨论Notch如何在选择以及其他谱系命运决定中发挥作用。
The Notch locus of Drosophila melanogaster is one of a small number of zygotically acting "neurogenic" genes involved in the correct segregation of neural from epidermal lineages during embryogenesis as well as in other postembryonic developmental events. We have generated antibody probes against three regions of the Notch protein to study the expression of Notch and begin a biochemical characterization of the protein. Consistent with predictions based on DNA sequence data, here we gather evidence showing that Notch encodes a large, glycosylated surface protein with an apparent molecular mass of 300 kD: (a) all three antibodies detect Notch on Western blots as a high molecular mass, primarily full-length product; (b) immunoelectron microscopy localizes the Notch protein to the cell membrane; and (c) lentil lectin column binding demonstrates ta the protein is glycosylated, indicative of its surface protein nature. In general, the distribution of the Notch protein coincides with that of the Notch transcript determined previously by in situ hybridizations. Notch is expressed in a much wider range of tissue types than those disrupted in the neurogenic mutant, as determined by antibody localization. Early labeling in the blastoderm appears ubiquitous except for the pole cells, but as development proceeds some distinctive features emerge: stronger staining is seen within the germ band layer where neuroblast delamination occurs, and the developing embryonic nervous system shows pronounced axonal staining. In third instar larvae, Notch is expressed in imaginal disks and in the central nervous system. Based on these results, certain models for how Notch controls the neuroblast cell fate choice are eliminated. We discuss how Notch may functions in the choice as well as in other lineage fate determinations.