Acute interstitial nephritis due to Leptospira grippotyphosa in the absence of Weil's disease.

Anicteric leptospirosis is a self-limited flu-like disease, whereas the icteric form is a severe illness characterized by multiple organ involvement or even failure. A case involving a patient with rapidly progressing renal insufficiency requiring intermittent renal replacement therapy due to Leptospira grippotyphosa in the absence of a Weil's disease is reported.

[When genetics matters: an unusual case of left-sided hemiparesis].

We report the case of a 35-year-old woman who has been admitted to our emergency room because of the sudden onset of a left-sided hemiparesis. The physical examination showed disseminated teleangiectases on the upper and lower lip, on the mucosal surface of the tongue and on the skin. The cerebral CT scan presented a right-sided fronto-parietal lesion, more likely an abscess, confirmed on surgical removal.

The Neurospora crassa gene responsible for the cut and ovc phenotypes encodes a protein of the haloacid dehalogenase family.

Light stimulation of carotenogenesis in Neurospora crassa, mediated by the White Collar proteins, is enhanced in some regulatory mutants, such as vivid and ovc. The gene responsible for the vivid mutation has been identified, but not the one responsible for the ovc phenotype. The ovc mutant is sensitive to high osmotic conditions and allelic with another mutant, cut, also osmosensitive but not affected in carotenogenesis.

Mutants of the carotene cyclase domain of al-2 from Neurospora crassa.

Phytoene synthase and carotene cyclase, two key enzymes in carotenoid biosynthesis, are encoded by two separate genes in bacteria and plants, but by a single bifunctional gene in fungi. The cyclase function has been demonstrated for the products of the genes crtYB from the basidiomycete Xanthophyllomyces dendrorhous, and for carRA and carRP from the zygomycetes Phycomyces blakesleeanus and Mucor circinelloides, respectively. These three genes are highly similar to al-2 from Neurospora crassa.

Genome analysis on linkage group VI of Neurospora crassa.

Two chromosome walks covering 420 and 110 kb on the left arm of linkage group VI (LGVIL) of Neurospora crassa were purscrooued with the goal of cloning carotenogenic loci. Complementation analysis with clones isolated in the 420-kb walk allowed identification of the yellow-1 (ylo-1) gene which is essential for Neurospora carotenogenesis. We have physically located a second gene, unknown-13 (un-13), between the cross-pathway control-1, (cpc-1) and ylo-1 loci.

Genome analysis in Neurospora crassa; cloning of four loci arginine-1 (arg-1), methionine-6 (met-6), unknown-7 (un-7), and ribosome production-1 (rip-1) and associated chromosome walking.

We have cloned four Neurospora crassa genes by complementation analysis. Cloned genes include the arginine-1 (arg-1), methionine-6 (met-6), unknown-7 (un-7), and ribosome production-1 (rip-1) loci. Chromosome walks were initiated in ordered cosmid libraries from the cloned loci.

Developmental and Photoregulation of Three Neurospora crassa Carotenogenic Genes during Conidiation Induced by Desiccation.

Neurospora crassa asexual sporulation (conidiation) is induced by different cues including desiccating aerial environments. Three of the genes that are expressed during this developmental pathway are the albino (al) genes, which encode carotenoid biosynthetic enzymes. If conidiation is induced by nutrient deprivation in liquid culture, two overlapping al-3 mRNAs, al-3 (m) and al-3 (c), are expressed (Arpaia et al.

Transgene silencing of the al-1 gene in vegetative cells of Neurospora is mediated by a cytoplasmic effector and does not depend on DNA-DNA interactions or DNA methylation.

The molecular mechanisms involved in transgene-induced gene silencing ('quelling') in Neurospora crassa were investigated using the carotenoid biosynthetic gene albino-1 (al-1) as a visual marker. Deletion derivatives of the al-1 gene showed that a transgene must contain at least approximately 132 bp of sequences homologous to the transcribed region of the native gene in order to induce quelling. Transgenes containing only al-1 promoter sequences do not cause quelling.

Developmental and photoregulation of three Neurospora crassa carotenogenic genes during conidiation induced by desiccation.

Neurospora crassa asexual sporulation (conidiation) is induced by different cues including desiccating aerial environments. Three of the genes that are expressed during this developmental pathway are the albino (al) genes, which encode carotenoid biosynthetic enzymes. If conidiation is induced by nutrient deprivation in liquid culture, two overlapping al-3 mRNAs, al-3 (m) and al-3 (c), are expressed (Arpaia et al.

Developmental and photoregulation of al-1 and al-2, structural genes for two enzymes essential for carotenoid biosynthesis in Neurospora.

The levels of al-1 and al-2 transcripts change dramatically in response to light and development during the formation of Neurospora crassa asexual spores (conidia). al-1 and al-2 mRNAs accumulate throughout conidiation irrespective of lighting conditions initially at low levels. As conidiation proceeds, two increases in albino message accumulation are observed.

Characterization of al-2, the phytoene synthase gene of Neurospora crassa. Cloning, sequence analysis, and photoregulation.

We have cloned the al-2 gene of Neurospora crassa and have analyzed its structure and regulation. The gene encodes a 603-residue polypeptide with a segment homologous to prokaryotic and other eukaryotic phytoene synthases. RNA measurements showed that the level of al-2 mRNA increased over 30-fold in photoinduced mycelia compared with dark-grown mycelia.

Cloning, sequence, and photoregulation of al-1, a carotenoid biosynthetic gene of Neurospora crassa.

Carotenoid biosynthesis is regulated by blue light during growth of Neurospora crassa mycelia. We have cloned the al-1 gene of N. crassa encoding the carotenoid-biosynthetic enzyme phytoene dehydrogenase and present an analysis of its structure and regulation.

Carotenoid desaturases from Rhodobacter capsulatus and Neurospora crassa are structurally and functionally conserved and contain domains homologous to flavoprotein disulfide oxidoreductases.

The characteristic red color of some photosynthetic bacteria and the orange color of Neurospora conidia is due to the presence of carotenoids, photoprotective pigments synthesized by plants, algae, bacteria, and fungi. Generally, carotenoids are tetraterpenes in which absorption of visible light and photoprotection are mediated by a chain of conjugated double bonds, the chromophore, which is formed by successive desaturations of phytoene, a colorless precursor. The genes al-1 and crtI mediate the desaturation of phytoene in Neurospora crassa and Rhodobacter capsulatus, respectively.

Host-specific effects of the korA-korB operon and oriT region on the maintenance of miniplasmid derivatives of broad host-range plasmid RK2.

Two genetic determinants are sufficient for small derivatives of broad host-range plasmid RK2 to replicate in different Gram-negative bacteria: trfA, which encodes a replication initiator, and oriV, the origin of replication. In this study, nonessential RK2 determinants in the region encoding oriT, the origin of conjugative transfer, and the korA-korB operon, whose products regulate trfA expression, were tested for their effects on the stability of mini-RK2 plasmids in eight different hosts. We found that determinants of both regions can substantially alter plasmid stability, but the effects are not uniform in all hosts.

Regions of broad-host-range plasmid RK2 involved in replication and stable maintenance in nine species of gram-negative bacteria.

The replication and maintenance properties of the broad-host-range plasmid RK2 and its derivatives were examined in nine gram-negative bacterial species. Two regions of RK2, the origin of replication (oriV) and a segment that encodes for a replication protein (trfA delta kilD, designated trfA*), are sufficient for replication in all nine species tested. However, stable maintenance of this minimal replicon (less than 0.

Comparison of 10 IncP plasmids: homology in the regions involved in plasmid replication.

We have examined the DNA homology in the replication regions of 10 IncP plasmids independently isolated from several different countries. Two regions of RK2, the best-studied plasmid of this group, are required for vegetative DNA replication: the origin of replication (oriV) and the trfA region, which codes for a gene product necessary for replication. Six of nine IncP plasmids studied were identical to RK2 in the oriV and trfA regions as shown by Southern hybridization.

Plasmids related to the broad host range vector, pRK290, useful for gene cloning and for monitoring gene expression.

Derivatives of plasmid pRK290 that are useful for cloning and for analyzing gene expression in a wide variety of Gram-negative bacteria are described. A smaller broad host range plasmid derived from RK2, with properties similar to that of pRK290, is also described.

Replication of derivatives of the broad host range plasmid RK2 in two distantly related bacteria.

A 0.7-kb segment of the broad host range plasmid RK2 containing the replication origin of this plasmid will replicate in Escherichia coli and Pseudomonas putida when this segment is joined to a 1.8-kb region of RK2 designated traA*.