State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China; email:
Institut WUT-AMU, Aix-Marseille Université and Wuhan University of Technology, Wuhan, Hubei, China.
Annu Rev Microbiol. 2022 Sep 8;76:597-618. doi: 10.1146/annurev-micro-041320-093442. Epub 2022 Jun 7.
Heterocyst differentiation that occurs in some filamentous cyanobacteria, such as sp. PCC 7120, provides a unique model for prokaryotic developmental biology. Heterocyst cells are formed in response to combined-nitrogen deprivation and possess a microoxic environment suitable for nitrogen fixation following extensive morphological and physiological reorganization. A filament of is a true multicellular organism, as nitrogen and carbon sources are exchanged among different cells and cell types through septal junctions to ensure filament growth. Because heterocysts are terminally differentiated cells and unable to divide, their activity is an altruistic behavior dedicated to providing fixed nitrogen for neighboring vegetative cells. Heterocyst development is also a process of one-dimensional pattern formation, as heterocysts are semiregularly intercalated among vegetative cells. Morphogens form gradients along the filament and interact with each other in a fashion that fits well into the Turing model, a mathematical framework to explain biological pattern formation.
某些丝状蓝藻（如 sp. PCC 7120）中的异形胞分化为原核生物发育生物学提供了一个独特的模型。异形胞是在氮饥饿的条件下形成的，具有微氧环境，非常适合进行固氮作用，同时伴随着广泛的形态和生理重组。 丝状体是一种真正的多细胞生物，因为氮源和碳源通过隔膜连接处在不同细胞和细胞类型之间进行交换，以确保丝状体的生长。由于异形胞是终末分化的细胞，不能分裂，因此它们的活动是一种利他行为，专门为邻近的营养细胞提供固定氮。异形胞的发育也是一个一维模式形成的过程，因为异形胞在营养细胞之间半规则地插入。形态发生素沿丝状体形成梯度，并以一种非常适合图灵模型的方式相互作用，图灵模型是一个解释生物模式形成的数学框架。
