The regionalisation of growing tissues into compartments that do not mix is thought to be a common motif of animal development. Compartments and compartmental boundaries were discovered by lineage studies in the model organism Drosophila. Since then, many compartment boundaries have been identified in developing tissues, from insects to vertebrates. These are important for animal development, because boundaries localize signalling centres that control tissue morphogenesis. Compartment boundaries are boundaries of lineage restriction, where specific mechanisms keep boundaries straight and cells segregated. Here, we review the mechanisms of cell sorting at boundaries found in early Drosophila embryos. The parasegmental boundaries, separating anterior from posterior compartments in the embryo, keep cells segregated by increasing actomyosin contractility at boundary cell-cell interfaces. Differential actomyosin contractility in turn promotes fold formation and orients cell division. Earlier in development, actomyosin differentials are also important for cell sorting during axis extension. Specific cell surface asymmetries and signalling pathways are required to initiate and maintain these actomyosin differentials.

将生长组织区域化为不混合的隔室被认为是动物发育的常见主题。隔室和隔室边界是通过模式生物果蝇的谱系研究发现的。从那时起，从昆虫到脊椎动物的发育组织中已经确定了许多隔室边界。这些对动物发育很重要，因为边界定位控制组织形态发生的信号中心。隔间边界是谱系限制的边界，其中特定机制保持边界直线和细胞隔离。在这里，我们回顾了在早期果蝇中发现的边界细胞分选机制胚胎。节段旁边界将胚胎中的前隔室与后隔室分开，通过增加边界细胞 - 细胞界面处的肌动球蛋白收缩力来保持细胞分离。不同的肌动球蛋白收缩性反过来促进折叠形成和定向细胞分裂。在开发早期，肌动球蛋白差异对于轴延伸过程中的细胞分选也很重要。需要特定的细胞表面不对称和信号通路来启动和维持这些肌动球蛋白差异。