|
|
Vegetative incompatibility in filamentous ascomycetes
Glässnerová, Kateřina ; Hubka, Vít (advisor) ; Sklenář, František (referee)
Vegetative incompatibility is a process occurring during vegetative growth in filamentous fungi which can prevent fusion of hyphae between individuals. In case of hyphal fusion between two individuals with genetically incompatible combination of alleles of vegetative incompatibility genes (i.e. het or vic genes), the newly-emerged heterokaryotic cell is destroyed via programmed cell death, which can be mediated in various ways. The purpose of this mechanism can be to preserve the genetic individuality of an individual or to prevent the transmission of a deleterious cytoplasmatic elements (e.g. mycoviruses). Exploring the vegetative incompatibility genes plays an important role for example in the induction of sexual state in vitro or in the study of speciation mechanisms in fungi. On the molecular-genetic level, vegetative incompatibility has been so far described in detail only in three ascomycete species. This thesis aims to summarize our knowledge concerning the significance of vegetative incompatibility and genetical mechanisms that underlie this process. Key words: vegetative incompatibility, het genes, vic genes, mat locus, programmed cell death, Neurospora crassa, Podospora anserina, Cryphonectria parasitica
|
|
|
Recombinant expresion and purification of nitrilase from Neurospora crassa
Zawadová, Dorota ; Vaněk, Ondřej (advisor) ; Kavan, Daniel (referee)
Nitrilases are enzymes able to convert toxic nitriles to corresponding carboxylic acids or amides. Thus they might be used in the detoxification of dyes, herbicides and pharmaceutical intermediates and byproducts. They can be used also for enzymatic syntheses of carboxylic acids not available by standard procedures. The aim of this diploma thesis is a recombinant expression of nitrilases from Neurospora crassa and the optimization of their purification. Cells of E. coli (BL 21 Gold) were utilized as an expression system. The purification was performed by ion-exchange chromatography, chelation chromatography and gel filtration - all under reducing conditions. Purified enzymes were studied by sedimentation analysis in an analytical ultracentrifuge. They were also used for searching of optimal conditions for their crystallization. Keywords: nitrilase, Neurospora crassa, recombinant expression
|
guest ::
