Patel N H, Kornberg T B, Goodman C S
Howard Hughes Medical Institute, Department of Biochemistry, University of California, Berkeley 94720.
Development. 1989 Oct;107(2):201-12. doi: 10.1242/dev.107.2.201.
We have used a monoclonal antibody that recognizes engrailed proteins to compare the process of segmentation in grasshopper, crayfish, and Drosophila. Drosophila embryos rapidly generate metameres during an embryonic stage characterized by the absence of cell division. In contrast, many other arthropod embryos, such as those of more primitive insects and crustaceans, generate metameres gradually and sequentially, as cell proliferation causes caudal elongation. In all three organisms, the pattern of engrailed expression at the segmented germ band stage is similar, and the parasegments are the first metameres to form. Nevertheless, the way in which the engrailed pattern is generated differs and reflects the differences in how these organisms generate their metameres. These differences call into question what role homologues of the Drosophila pair-rule segmentation genes might play in other arthropods that generate metameres sequentially.
我们使用了一种能识别engrailed蛋白的单克隆抗体，来比较蚱蜢、小龙虾和果蝇的体节形成过程。果蝇胚胎在一个以无细胞分裂为特征的胚胎阶段迅速产生体节。相比之下，许多其他节肢动物胚胎，如更原始昆虫和甲壳类动物的胚胎，随着细胞增殖导致尾部伸长，会逐渐且依次地产生体节。在所有这三种生物中，在分节胚带阶段engrailed基因的表达模式是相似的，并且副体节是最早形成的体节。然而，engrailed基因模式的产生方式有所不同，这反映了这些生物产生体节方式的差异。这些差异让人质疑果蝇成对规则分节基因的同源物在其他依次产生体节的节肢动物中可能发挥什么作用。
