Scholtz G, Patel N H, Dohle W
Institut für Zoologie, Freie Universität Berlin, Germany.
Int J Dev Biol. 1994 Sep;38(3):471-8.
A monoclonal antibody (mAb 4D9) was used to analyze engrailed expression in amphipod embryos. As in other arthropods, engrailed is expressed in iterated transverse stripes in the germ band. In the anterior region these stripes are generated without a recognizable division pattern, and their appearance and formation show some irregularities. In the posterior region of the germ band, engrailed expression is correlated with a stereotyped cell division pattern resulting in a highly ordered formation and array of stripes. The engrailed positive cells mark the anterior border of genealogical units, which therefore can be compared with parasegments in Drosophila. Expression starts in the mandibular segment and proceeds first anteriorly and subsequently in a posterior direction. Initial stripes are one cell wide. The widening of stripes is caused by both division of engrailed positive cells and recruitment of new cells that did not previously express engrailed. The widening process is related to segment formation as the intersegmental furrows are established behind the engrailed expressing cells, which are restricted to the posterior portion of the forming segments. A comparison of the modes of engrailed expression in different segments suggests that initial engrailed expression is independent of a certain cell lineage or division pattern. The comparison of the development of the early engrailed stripes in different insects and crustaceans reveals some similarities which show that early engrailed expression is not necessarily clonally inherited.
一种单克隆抗体（mAb 4D9）被用于分析端足目胚胎中engrailed基因的表达。与其他节肢动物一样，engrailed基因在胚带中呈重复的横向条纹表达。在胚胎前部区域，这些条纹的产生没有可识别的分裂模式，其出现和形成表现出一些不规则性。在胚带的后部区域，engrailed基因的表达与一种固定的细胞分裂模式相关，导致条纹以高度有序的方式形成和排列。engrailed阳性细胞标记了谱系单位的前缘，因此可以与果蝇中的副节进行比较。表达从下颌节开始，先向前进行，随后向后进行。最初的条纹宽一个细胞。条纹的加宽是由engrailed阳性细胞的分裂和新细胞的招募引起的，这些新细胞以前不表达engrailed基因。加宽过程与节段形成有关，因为节间沟在engrailed表达细胞后方形成，而engrailed表达细胞局限于形成节段的后部。不同节段中engrailed基因表达模式的比较表明，engrailed基因的初始表达独立于特定的细胞谱系或分裂模式。不同昆虫和甲壳类动物早期engrailed条纹发育的比较揭示了一些相似之处，表明早期engrailed基因的表达不一定是克隆遗传的。
