Deutsch A, Dress A, Rensing L
Department of Biology, University of Bremen, Germany.
Mech Dev. 1993 Nov;44(1):17-31. doi: 10.1016/0925-4773(93)90013-n.
Morphological differentiation patterns--among them concentric rings and radial zonations--can be induced in the band-mutant of Neurospora crassa by appropriate experimental conditions, in particular by a mere shift of certain salt concentrations in the medium. The role of initial experimental conditions is examined and, furthermore, the influences of artificially induced phase differences are analyzed with respect to pattern formation. While the concentric ring pattern is due to some (endogenous) circadian rhythmicity within every hypha, nothing is known about the underlying mechanism of radial zonation development. Various hypotheses were tested with the help of a cellular automaton model which mimics growth, branching and differentiation of a fungal mycelium. In particular, sufficient conditions are provided which imply the formation of radial spore zonations. These conditions postulate a rather homogeneous microscopic hyphal branching pattern and induction of spore differentiation by means of an activator-inhibitor system. Furthermore, a working hypothesis for the formation of spore patterns in Neurospora crassa is suggested which is based on an extracellular control of fungal differentiation.
形态分化模式——包括同心环和径向分区——可以在粗糙脉孢菌的条带突变体中通过适当的实验条件诱导产生，特别是通过仅仅改变培养基中某些盐的浓度。研究了初始实验条件的作用，此外，还分析了人工诱导的相位差对模式形成的影响。虽然同心环模式是由于每个菌丝内存在某种（内源性）昼夜节律，但对于径向分区发育的潜在机制尚不清楚。借助模拟真菌菌丝体生长、分支和分化的细胞自动机模型，对各种假设进行了测试。特别地，提供了足以形成径向孢子分区的条件。这些条件假定了相当均匀的微观菌丝分支模式，并通过激活剂-抑制剂系统诱导孢子分化。此外，还提出了一个基于真菌分化的细胞外控制的粗糙脉孢菌孢子模式形成的工作假设。
