uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Physiological and Genetic Characterisation of some Aphanomyces Strains Isolated from Freshwater Crayfish
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Evolutionary Biology, Comparative Physiology.
Show others and affiliations
Manuscript (Other academic)
URN: urn:nbn:se:uu:diva-89577OAI: oai:DiVA.org:uu-89577DiVA: diva2:161178
Available from: 2001-12-20 Created: 2001-12-20 Last updated: 2010-01-13Bibliographically approved
In thesis
1. Differentiation and Pathogenicity within the Saprolegniaceae: Studies on Physiology and Gene Expression Patterns in Saprolegnia parasitica and Aphanomyces astaci
Open this publication in new window or tab >>Differentiation and Pathogenicity within the Saprolegniaceae: Studies on Physiology and Gene Expression Patterns in Saprolegnia parasitica and Aphanomyces astaci
2001 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Saprolegnia parasitica and Aphanomyces astaci are parasitic water moulds belonging to the Oomycetes. Despite their importance as parasites they are very little studied at the molecular level and the work described in this thesis was aimed at increasing the molecular knowledge of these organisms by cloning and characterising genes of potential importance for reproduction and pathogenicity.

Stage-specific transcripts from Saprolegnia parasitica were isolated by differential display RT-PCR. One of the markers, puf1 encodes a putative mRNA binding protein which may be involved in post-transcriptional regulation of gene expression. S. parasitica puf1 is expressed exclusively in spore cysts that have not been determined for germination or repeated zoospore emergence indicating that the cyst stage has two phases, of about equal duration, which are physiologically and transcriptionally distinct. A similar expression pattern is observed in Aphanomyces spp. with different regulation of spore development and in the transcript is detected in both primary and secondary cysts.

A putative chitinase AaChi1, was cloned from the crayfish plague fungus, Aphanomyces astaci. Analysis of chitinase activity and AaChi1 expression showed that chitinase in A. astaci is constitutively expressed in growing and sporulating mycelia, but absent in zoospores, a pattern which reflects the infectious life cycle of A. astaci. This expression pattern is conserved between the four known genotypes of A. astaci, in contrast to saprophytic and fish-pathogenic Aphanomyces spp.

Genetic and physiological analysis were conducted on five strains of Aphanomyces, isolated from suspected outbreaks of crayfish plague in Spain and Italy. The strains are not virulent against freshwater crayfish, and RAPD PCR and ITS sequence analysis show that they are unrelated to the crayfish plague fungus, A. astaci.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2001. 41 p.
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 680
Zoophysiology, Zoofysiologi
National Category
Research subject
Physiological Mycology
urn:nbn:se:uu:diva-1592 (URN)91-554-5203-5 (ISBN)
Public defence
2002-02-01, Lindahl salen, Uppsala, 10:00
Available from: 2001-12-20 Created: 2001-12-20Bibliographically approved

Open Access in DiVA

No full text

By organisation
Comparative Physiology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 267 hits
ReferencesLink to record
Permanent link

Direct link