| Title | Ultrastructure of the Cell Wall of a Null Pigmentation Mutant, npgA1, in Aspergillus nidulans |
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| Author | Yun Shin Chung 1 , § , Jung-Mi Kim 1 , Dong-Min Han 2 , Keon-Sang Chae 1 and Kwang-Yeop Jahng 1 , * |
| Address | 1 Division of Biological Sciences, Institute for Molecular Biology and Genetic Engineering, Institute for Basic Sciences, Chonbuk National University, Chonju 561-756, Korea ; 2 Division of Life Sciences, Wonkwang University, Iksan 570-749, Korea (Received March 18, 2003 / Accepted July 28, 2003) |
| Bibliography | Journal of Microbiology, 41(3),224-231, 2003, |
| DOI | |
| Key Words | Aspergillus nidulans, npgA, ultrastructure |
| Abstract | The null pigmentation mutant (npgA1) of Aspergillus nidulans was previously characterized by its production of no pigment at any stage of its life cycle, its reduction in hyphal branching, and its delay in the asexual spore development. The chemical composition of the cell wall was also altered in npgA1 mutants that became more sensitive to Novozyme 234_TM, which is possibly due to a structural defect in the cell wall. To investigate the effects of the cell wall structure on these pleiomorphic phenomena, we examined the ultrastructure of the cell wall in the npgA1 mutant (WX17). Scanning electron micrographs (SEM) showed that after being cultured for six days, the outermost layer of the conidial wall of WX17 peeled off. Although this phenotype suggested that the cell wall structure in WX17 may be modified, examination using TEM of the fine structure of cross-sectioned hyphal wall of WX17 did not show any differences from that of FGSC4. However, staining for carbohydrates of wall layers showed that the electron-translucent layer of the cell wall was missing in WX17. In addition, the outermost layer H1 of the hyphal wall was also absent in WX17. The ultrastructural observation and cytochemical analysis of cell walls suggested that the pigmentation defect in WX17 may be attributed to the lack of a layer in the cell wall. |
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