Divergence Between Sympatric Rice- and Soybean-Infecting Populations of Rhizoctonia solani Anastomosis Group-1 IA

Rhizoctonia solani anastomosis group (AG)-1 IA causes soybean foliar blighting (aerial blight) and rice sheath blight diseases. Although taxonomically related within the AG-1 complex, sister populations of R. solani AG-1 IA infecting Poaceae (rice) and Fabaceae (soybean) are genetically distinct based on internal transcribed spacer rDNA. However, there is Currently no information available regarding the extent of genetic differentiation and host specialization between rice- and soybean-infecting populations of R. solani AG-1 IA. We used 10 microsatellite loci to compare sympatric R. solani AG-1 IA populations infecting rice and soybeans in Louisiana and one allopatric rice-infecting population from Texas. None of the 154 multilocus genotypes found among the 223 isolates were shared among the three populations. Partitioning of genetic diversity showed significant differentiation among sympatric populations from different host Species (Phi(ST) = 0.39 to 0.41). Historical migration patterns between sympatric rice- and soybean-infecting populations from Louisiana were asymmetrical. Rice- and soybean-derived isolates of R. solani AG-1 IA were able to infect both rice and soybean, but were significantly more aggressive on their host of on-in, consistent with host specialization. The soybean-infecting Population from Louisiana was more clonal than the sympatric rice-infecting population. Most of the loci in the soybean-infecting populations were Out of Hardy-Weinberg equilibrium (HWE.), but the sympatric rice-infecting population from Louisiana was mainly in HWE. All populations presented evidence for a mixed reproductive system.

Morphological and molecular characterization of an equine isolate of Pythium insidiosum and comparison with the first human isolate from the same geographic region

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Phenotypic and genotypic characterization of Prototheca zopfii in a dog with enteric signs

This is a case report of enteric protothecosis caused by Prototheca zopfii in an eight-year-old male mixed breed dog with a history of chronic bloody diarrhea, loss of appetite and weight loss. Algae were isolated from rectal scrapings in defibrinated sheep blood agar and dextrose Sabouraud agar. Cytological evaluation showed the presence of globular and cylindrical organisms with a defined capsule and variable number of endospores, characteristic of the genus Prototheca, in the rectum of the animal. Scanning electron microscopy of P. zopfii strains at different development stages confirmed the diagnosis of algal infection. Molecular identification using a conserved 18S rDNA gene sequence determined that the strain belonged to genotype 2. This report describes success on treatment of canine protothecosis, diagnosed based on clinical, cytological, microbiological, scanning electron microscopy and genotypical findings. (c) 2009 Elsevier Ltd. All rights reserved.

Antigenicity of Primary Endodontic Infection against Macrophages by the Levels of PGE(2) Production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antigenic Activity of Bacterial Endodontic Contents from Primary Root Canal Infection with Periapical Lesions against Macrophage in the Release of Interleukin-1 beta and Tumor Necrosis Factor alpha

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Correlation between Clinical/Radiographic Features and Inflammatory Cytokine Networks Produced by Macrophages Stimulated with Endodontic Content

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ecological study of Paracoccidioides brasiliensis in soil: growth ability, conidia production and molecular detection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Molecular detection of Paracoccidioides brasiliensis in soil

The objective of the present study was to evaluate different techniques for the detection of Paracoccidioides brasiliensis in soil, e.g., culture, animal inoculation and specific DNA amplification by Nested PCR. We designed species-specific inner primers derived from rDNA regions (ITS, 5.8S gene) and found their sensitivity to be higher than culture and animal inoculation. In addition, the sensitivity of these primers was higher than p27-gene primers developed for detection of P brasiliensis in soil in a previous study. DNA from P brasiliensis was detected in soil artificially seeded with the fungus (positive soil control) and from environmental samples collected in an armadillo burrow.

Genomic organization and evolution of the 5S ribosomal DNA in Tilapiini fishes

5S rDNA sequences present an intense dynamism and have proved to be valuable as genetic markers to distinguish closed related species and also in the understanding of the evolutionary dynamic of repetitive sequences in the genomes. In order to identify patterns of 5S rDNA organization and their evolution in the genome of fish species, such genomic segment was investigated in the tilapias Oreochromis niloticus and Tilapia rendalli, and in the hybrid O. urolepis hornorum x O. mossambicus. A dual 5S rDNA system was identified in the three analyzed tilapia samples. Although each 5S rDNA class was conserved among the three samples, a distinct 5S rDNA genome organization pattern could be evidenced for each sample. The presence of a dual 5S rDNA system seems to be a general trait among non-related teleost fish orders, suggesting that evolutionary events of duplication have occurred before the divergence of the main groups of teleost fishes.

NORs inheritance analysis in crossings including individuals from two stocks of rainbow trout (Oncorhynchus mykiss)

Silver nitrate staining of rainbow trouts (Oncorhynchus mykiss) chromosomes, for the identification of the nucleolar organizing regions (NORs), revealed that in individuals from Nucleo Experimental de Salmonicultura de Campos do Jordao (Brazil) NORs were located in the long arms of a submetacentric pair while in specimens from Mount Shasta (USA) NORs were located in the short arms of a submetacentric pair. Cytogenetic analysis of the offspring, obtained through artificial crosses including individuals from both stocks, allowed the identification of NORs in two submetacentric chromosomes, one in the short arms and the other in the long arms, confirming the effectiveness of the hybridization process. Complementary results obtained using the FISH technique with 18S and 5S rDNA probes showed that NOR-bearing chromosomes exhibited a cluster of 5S genes located in tandem with the 18S gene cluster in both stocks. The results allow us to suggest that the difference in NOR-bearing chromosomes found between the two stocks is likely to be due to a pericentric inversion involving the chromosome segment where 18S and 5S rDNA genes are located. The presence of ribosomal genes in the long arms of a submetacentric chromosome is apparently a particular characteristic of the rainbow trout stock of Campos do Jordao and might be used as a chromosome marker in studies of controlled crosses in this species.

Cytogenetic analysis of three species of the genus Haemulon (Teleostei : Haemulinae) from Margarita Island, Venezuela

This paper describes the karyotype analysis of Haemulon aurolineatum, Haemulon bonariensis and Haemulon plumierii, by Giemsa staining, C-banding, Ag-staining and fluorescent in situ hybridization (FISH), to locate the 18S and 5S rRNA genes. Diploid modal count in the three species was 2n = 48 acrocentric elements. Except for pair 24, which exhibited an unmistakable secondary constriction in all three species, it was not possible to classify them as homologous to each other because differences in chromosome size were too slight between adjacent pairs within a size-graded series. Ag-NOR clusters were located in pair 24 in the three species with signal located on the secondary constriction of these chromosomes. C-banding demonstrated that the three species share the same distribution pattern of the constitutive heterochromatin with centromeric heterochromatic blocks in the 23 chromosome pairs and a pericentromeric block in pair 24 which is coincident with the NORs. FISH experiments showed that 18S rDNA sequences were located coincident with the Ag-NOR site in the three species; however, differences in both the number and chromosome distribution of 5S-rDNA cluster were detected among them. Our data suggest that chromosome evolution of Haemulon has been preserved from major changes in the karyotypic macrostructure, whereas microstructural changes have occurred.

A comparative structural cytogenetic study in three allopatric populations of Astyanax scabripinnis (Teleostei: Characidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Karyotype characterization of Mugil incilis Hancock, 1830 (Mugiliformes: Mugilidae), including a description of an unusual co-localization of major and minor ribosomal genes in the family

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cytogenetic characterization of Rhomboplites aurorubens and Ocyurus chrysurus, two monotypic genera of Lutjaninae from Cubagua Island, Venezuela, with a review of the cytogenetics of Lutjanidae (Teleostei: Perciformes)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)