Momany M, Westfall P J, Abramowsky G
Department of Botany, University of Georgia, Athens, Georgia 30602, USA.
Genetics. 1999 Feb;151(2):557-67. doi: 10.1093/genetics/151.2.557.
When the spores of filamentous fungi break dormancy, they grow isotropically, adding cell wall material uniformly in every direction. Later they switch to polarized growth, with new material added to the tip of an emerging germ tube. To identify genes involved in the synthesis and localization of cell wall material in filamentous fungi, we screened a collection of temperature-sensitive Aspergillus nidulans mutants for swollen cells. We have isolated mutants representing eight genes involved in polarity establishment, polarity maintenance, and hyphal morphogenesis. On the basis of the results of temperature-shift experiments, swo C, D, and F are required to establish polarity, while swoA is required to maintain polarity. swo B, E, G, and H are involved in later hyphal morphogenesis. Our results suggest that polarity establishment and polarity maintenance are genetically separate events and that a persistent signal is required for apical extension in A. nidulans.
当丝状真菌的孢子打破休眠时，它们进行各向同性生长，在各个方向均匀地添加细胞壁物质。之后它们转变为极性生长，新物质添加到正在形成的芽管的顶端。为了鉴定参与丝状真菌细胞壁物质合成和定位的基因，我们筛选了一组温度敏感型构巢曲霉突变体以寻找肿胀细胞。我们分离出了代表八个参与极性建立、极性维持和菌丝形态发生的基因的突变体。根据温度转换实验的结果，swo C、D和F是建立极性所必需的，而swoA是维持极性所必需的。swo B、E、G和H参与后期的菌丝形态发生。我们的结果表明，极性建立和极性维持在遗传上是分开的事件，并且在构巢曲霉中顶端延伸需要持续的信号。
