FBS Colloquia No.342Laboratory of Pattern Formation

Mechanism by which produces the orientation pattern of collagen fibers supporting zebrafish fin formation

To build architectures, lumber or rebar and so on are used as frame. Forms of architectures depend on how to arrange the building materials. On body formation of vertebrate animals, collagen fiber is comparable to "building materials" as frame. Orientation patterns of collagen fibers differ depending on tissues, and the patterns are thought to be important in creating functional morphology of each tissue. On construction process of architectures, human can carry out construction work based on blueprint. However, on body formation process, how cells control collagen fibers orientation and form tissues is poorly understood. We have focused on the morphogenesis of zebrafish fins as an experimental model to address this question. In distal tip region of zebrafish fins, unique collagen fiber structure is unidirectionally distributed on fin plane. This orientation pattern works as frame of flat fin tissues. This structure is called actinotrichia, which plays an important role in forming straight fin ray bone and functional fin shape. In this study, we found that the orientation pattern of actinotrichia dramatically altered in the fins of specific gene knockout fish. By analyzing this mutant, we will approach mechanism by which produces orientation patterns of collagen fibers supporting tissue morphogenesis.