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Start Over Creator Vivarès, Christian P.

1. Chromosomal composition of the genome in the monomorphic diplokaryotic microsporidium Paranosema grylli: analysis by two-dimensional pulsed-field gel electrophoresis

Creator:
Nassonova, Elena, Cornillot, Emmanuel, Méténier, Guy, Agafonova, Nina, Kudryavtsev, Boris, Skarlato, Sergei, and Vivarès, Christian P.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Microsporidia, diplokaryon, molecular karyotype, KARD 2-D PFGE, chromosome-length polymorphism, ploidy, and meiosis
Language:
English
Description:
The molecular karyotype of Paranosema grylli Sokolova, Seleznev, Dolgikh et Issi, 1994, a monomorphic diplokaryotic microsporidium, comprises numerous bright and faint bands of nonstoichiometric staining intensity. Restriction analysis of chromosomal DNAs by ''karyotype and restriction display'' 2-D PFGE has demonstrated that the complexity of molecular karyotype of P. grylli is related to the pronounced length polymorphism of homologous chromosomes. The background of this phenomenon is discussed in the context of ploidy state, reproductive strategy and population structure in this microsporidium. We propose that the remarkable size variation between homologous chromosomes in P. grylli may be a consequence of ectopic recombination at the chromosome extremities.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Occurrence of the microsporidian parasite Nucleospora salmonis in four species of salmonids from the Massif Central of France

Creator:
El Alaoui, Hicham , Grésoviac, Stéphane J., and Vivarès, Christian P.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Microsporidia, Nucleospora salmonis, intranuclear parasite, salmonid fish, and rDNA
Language:
English
Description:
Nucleospora salmonis (Hedrick, Groff et Baxa, 1991), an intranuclear microsporidian parasite of marine and freshwater fish, causes diseases mainly in salmonid species. Losses have been reported in stocks of salmonid fish reared in the region of Auvergne (France). The cause of chronic mortalities in the local host species raised in aquaculture and destined for supplementation of the river system Loire-Allier was examined. The presence of N. salmonis was confirmed by PCR and histology in Salmo salar L. previously and in newly investigated salmonid species, Salmo salar, Salmo trutta fario L., Thymallus thymallus (L.) and Salvelinus alpinus (L.), present in European streams. The infection by N. salmonis was consistent in all cases with characteristic symptoms of the disease in deceased or moribund fish. The small subunit ribosomal DNA from N. salmonis was partially sequenced and compared to previously characterised N. salmonis isolates. As a result, a genotype, or clonal entity, was attributed to N. salmonis among Atlantic salmon found along the Northern Atlantic coastal lines and other salmonid species co-inhabiting or co-cultivated in the Auvergne region.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Post-genomics of microsporidia, with emphasis on a model of minimal eukaryotic proteome: a review

Creator:
Texier, Catherine, Brosson, Damien, El Alaoui, Hicham, Méténier, Guy, and Vivarès, Christian P.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Microsporidia, Encephalitozoon, intracellular parasite, post-genomics, protein size, deletions, and proteome analysis
Language:
English
Description:
The genome sequence of the microsporidian parasite Encephalitozoon cuniculi Levaditi, Nicolau et Schoen, 1923 contains about 2,000 genes that are representative of a non-redundant potential proteome composed of 1,909 protein chains. The purpose of this review is to relate some advances in the characterisation of this proteome through bioinformatics and experimental approaches. The reduced diversity of the set of E. cuniculi proteins is perceptible in all the compilations of predicted domains, orthologs, families and superfamilies, available in several public databases. The phyletic patterns of orthologs for seven eukaryotic organisms support an extensive gene loss in the fungal clade, with additional deletions in E. cuniculi. Most microsporidial orthologs are the smallest ones among eukaryotes, justifying an interest in the use of these compacted proteins to better discriminate between essential and non-essential regions. The three components of the E. cuniculi mRNA capping apparatus have been especially well characterized and the three-dimensional structure of the cap methyltransferase has been elucidated following the crystallisation of the microsporidial enzyme Ecm1. So far, our mass spectrometry-based analyses of the E. cuniculi spore proteome has led to the identification of about 170 proteins, one-quarter of these having no clearly predicted function. Immunocytochemical studies are in progress to determine the subcellular localisation of microsporidia-specific proteins. Posttranslational modifications such as phosphorylation and glycosylation are expected to be soon explored.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public