Nechiporuk Alex, Raible David W
University of Washington, School of Medicine, Department of Biological Structure, Seattle, WA 98195-7420, USA.
Science. 2008 Jun 27;320(5884):1774-7. doi: 10.1126/science.1156547.
During development, organ primordia reorganize to form repeated functional units. In zebrafish (Danio rerio), mechanosensory organs called neuromasts are deposited at regular intervals by the migrating posterior lateral line (pLL) primordium. The pLL primordium is organized into polarized rosettes representing proto-neuromasts, each with a central atoh1a-positive focus of mechanosensory precursors. We show that rosettes form cyclically from a progenitor pool at the leading zone of the primordium as neuromasts are deposited from the trailing region. fgf3/10 signals localized to the leading zone are required for rosette formation, atoh1a expression, and primordium migration. We propose that the fibroblast growth factor (FGF) source controls primordium organization, which, in turn, regulates the periodicity of neuromast deposition. This previously unrecognized mechanism may be applicable to understanding segmentation and morphogenesis in other organ systems.
在发育过程中,器官原基会重新组织形成重复的功能单元。在斑马鱼(Danio rerio)中,称为神经丘的机械感觉器官由迁移的后侧线(pLL)原基以规则的间隔沉积。pLL原基被组织成极化的玫瑰花结,代表原神经丘,每个原神经丘都有一个位于中心的atoh1a阳性机械感觉前体焦点。我们发现,随着神经丘从尾端区域沉积,玫瑰花结在原基前端区域的祖细胞池中周期性形成。定位在前导区的fgf3/10信号是玫瑰花结形成、atoh1a表达和原基迁移所必需的。我们提出,成纤维细胞生长因子(FGF)源控制原基组织,进而调节神经丘沉积的周期性。这种以前未被认识的机制可能适用于理解其他器官系统中的分割和形态发生。