• Title/Summary/Keyword: Ultrastructure

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Ultrastructure of the Cell Wall of a Null Pigmentation Mutant, npgA1, in Aspergillus nidulans

  • Chung, Yun-Shin;Kim, Jung-Mi;Han, Dong-Min;Chae, Keon-Sang;Jahng, Kwang-Yeop
    • Journal of Microbiology
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    • v.41 no.3
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    • pp.224-231
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    • 2003
  • 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.

Morphology and Ultrastructure of Gill for Lateolabrax japonicus (농어(Lateolabrax japonicus) 아가미의 형태와 미세구조)

  • Kang, Chung-Bae;Kim, Jin-Koo;Kim, Jae-Won
    • Applied Microscopy
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    • v.39 no.4
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    • pp.319-324
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    • 2009
  • Morphology of the gill in Lateolabrax japonicus was investigated after staining the gill, as a result, we found the gill is composed of gill raker, gill arch, gill filament and gill lamellae. The number of gill raker was 7~10 in the upper and 13~18 in the lower. Ultrastructure of the gill in Lateolabrax japonicus were examined by means of the light and transmission electron microscopes. The gill have primary filament and secondary filament (lamellae). The following cells are identified and described: pavement cell, pillar cell, blood cell, mucose cell and chloride cell etc. Simple epithelial layer consists of squamous epithelium contained large nucleus, intracellular organelles etc. and the surface is covered with some of microridges. The lamella pillar structures are characterized by the axial microtubules and lateral membrane interdigitations. The mucous cells were globular in shape, and had almost the mucous granules of same size with various electron density. Chloride cells contain a lot of mitochondria and specifically developed tubular systems.