Cytogenetic mapping of H1 histone and ribosomal RNA genes in hybrids between catfish species Pseudoplatystoma corruscans and Pseudoplatystoma reticulatum

A physical chromosome mapping of the H1 histone and 5S and 18S ribosomal RNA (rRNA) genes was performed in interspecific hybrids of Pseudoplatystoma corruscans and P. reticulatum. The results showed that 5S rRNA clusters were located in the terminal region of 2 chromosomes. H1 histone and 18S ribosomal genes were co-localized in the terminal portion of 2 chromosomes (distinct from the chromosomes bearing 5S clusters). These results represent the first report of association between H1 histone and 18S genes in fish genomes. The chromosome clustering of ribosomal and histone genes was already reported for different organisms and suggests a possible selective pressure for the maintenance of this association. © 2012 S. Karger AG, Basel.

Ultra-structural mapping of sugarcane bagasse after oxalic acid fiber expansion (OAFEX) and ethanol production by Candida shehatae and Saccharomyces cerevisiae

Background: Diminishing supplies of fossil fuels and oil spills are rousing to explore the alternative sources of energy that can be produced from non-food/feed-based substrates. Due to its abundance, sugarcane bagasse (SB) could be a model substrate for the second-generation biofuel cellulosic ethanol. However, the efficient bioconversion of SB remains a challenge for the commercial production of cellulosic ethanol. We hypothesized that oxalic-acid-mediated thermochemical pretreatment (OAFEX) would overcome the native recalcitrance of SB by enhancing the cellulase amenability toward the embedded cellulosic microfibrils. Results: OAFEX treatment revealed the solubilization of hemicellulose releasing sugars (12.56 g/l xylose and 1.85 g/l glucose), leaving cellulignin in an accessible form for enzymatic hydrolysis. The highest hydrolytic efficiency (66.51%) of cellulignin was achieved by enzymatic hydrolysis (Celluclast 1.5 L and Novozym 188). The ultrastructure characterization of SB using scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, Fourier transform-near infrared spectroscopy (FT-NIR), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) revealed structural differences before and after OAFEX treatment with enzymatic hydrolysis. Furthermore, fermentation mediated by C. shehatae UFMG HM52.2 and S. cerevisiae 174 showed fuel ethanol production from detoxified acid (3.2 g/l, yield 0.353 g/g; 0.52 g/l, yield, 0.246 g/g) and enzymatic hydrolysates (4.83 g/l, yield, 0.28 g/g; 6.6 g/l, yield 0.46 g/g). Conclusions: OAFEX treatment revealed marked hemicellulose degradation, improving the cellulases ability to access the cellulignin and release fermentable sugars from the pretreated substrate. The ultrastructure of SB after OAFEX and enzymatic hydrolysis of cellulignin established thorough insights at the molecular level. © 2013 Chandel et al; licensee BioMed Central Ltd.

SERS mapping in langmuir-blodgett films and single-molecule detection

Plasmon-enhanced spectroscopic techniques have expanded single-molecule detection (SMD) and are revolutionizing areas such as bio-imaging and single-cell manipulation. Surface-enhanced (resonance) Raman scattering (SERS or SERRS) combines high sensitivity with molecularfingerprint information at the single-molecule level. Spectra originating from single-molecule SERS experiments are rare events, which occur only if a single molecule is located in a hot-spot zone. In this spot, the molecule is selectively exposed to a significant enhancement associated with a high, local electromagnetic field in the plasmonic substrate. Here, we report an SMD study with an electrostatic approach in which a Langmuir film of a phospholipid with anionic polar head groups (PO 4 -) was doped with cationic methylene blue (MB), creating a homogeneous, two-dimensional distribution of dyes in the monolayer. The number of dyes in the probed area of the Langmuir-Blodgett (LB) film coating the Ag nanostructures established a regime in which single-molecule events were observed, with the identification based on direct matching of the observed spectrum at each point of the mapping with a reference spectrum for the MB molecule. In addition, advanced fitting techniques were tested with the data obtained from micro-Raman mapping, thus achieving real-time processing to extract the MB single-molecule spectra. © 2013 Society for Applied Spectroscopy.

Chromosomal Mapping of Repetitive DNAs in the Grasshopper Abracris flavolineata Reveal Possible Ancestry of the B Chromosome and H3 Histone Spreading

Supernumerary chromosomes (B chromosomes) occur in approximately 15% of eukaryote species. Although these chromosomes have been extensively studied, knowledge concerning their specific molecular composition is lacking in most cases. The accumulation of repetitive DNAs is one remarkable characteristic of B chromosomes, and the occurrence of distinct types of multigene families, satellite DNAs and some transposable elements have been reported. Here, we describe the organization of repetitive DNAs in the A complement and B chromosome system in the grasshopper species Abracris flavolineata using classical cytogenetic techniques and FISH analysis using probes for five multigene families, telomeric repeats and repetitive C0t-1 DNA fractions. The 18S rRNA and H3 histone multigene families are highly variable and well distributed in A. flavolineata chromosomes, which contrasts with the conservation of U snRNA genes and less variable distribution of 5S rDNA sequences. The H3 histone gene was an extensively distributed with clusters occurring in all chromosomes. Repetitive DNAs were concentrated in C-positive regions, including the pericentromeric region and small chromosomal arms, with some occurrence in C-negative regions, but abundance was low in the B chromosome. Finally, the first demonstration of the U2 snRNA gene in B chromosomes in A. flavolineata may shed light on its possible origin. These results provide new information regarding chromosomal variability for repetitive DNAs in grasshoppers and the specific molecular composition of B chromosomes. © 2013 Bueno et al.

Palaeosurfaces mapping and associated supergene copper deposits identification as mineral exploration tool Itapeva and Ribeirão Branco region – Ribeira Valley, state of São Paulo, Brazil

Alguns exemplos de formação de minério supérgeno e sua interação com a morfogênese (paleosuperfícies) e resistência mineralógica são discutidas aqui. Registros geomorfológicos e mineralógicos na caracterização paleosuperfícies associam o intemperismo de minerais primários e sua relação com as concentrações de cobre e minério de ferro no sudeste do estado de São Paulo, Brasil. Distinguiram-se duas paleosuperfícies geradas por várias fases de intemperismo e controladas pela estrutura geológica. A primeira, mais antiga, é a paleosuperfície superior (900 - 1000 m de altitude), situado em Ribeirão Branco (Alto do Brancal), foram desenvolvidas em rochas silico-calcários. É formada por lateritas de ferro enriquecido por produtos secundários de cobre. O segundo nível de paleosuperfície é mais novo está localizado na região de Itapeva (Santa Blandina e Bairro do Sambra). Esta paleosuperfície é formada por percolação de cobre através da rocha alterada (saprolito). Outras características podem ser observadas como produtos neoformados em lateritas. Eles são classificados em dois tipos: a argila como produtos silico-cuprífero (com quantidades significativas de ferro) e de cobre minerais (crisocola, fixas nas vertentes). Essas feições reconheceram a presença de minérios de cobre e seu controle morfogénetico ajudando na exploração e prospecção de minérios supérgenos.

Characterization, subsite mapping and N-terminal sequence of miliin, a serine-protease isolated from the latex of Euphorbia milii

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

Microsatellite Organization in the Grasshopper Abracris flavolineata (Orthoptera: Acrididae) Revealed by FISH Mapping: Remarkable Spreading in the A and B Chromosomes

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

Diagnostics of equatorial and low latitude ionosphere by TEC mapping over Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Delimiting the Origin of a B Chromosome by FISH Mapping, Chromosome Painting and DNA Sequence Analysis in Astyanax paranae (Teleostei, Characiformes)

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

Composite interval mapping and mixed models reveal QTL associated with performance and carcass traits on chicken chromosomes 1, 3, and 4

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

Chromosomal Mapping of Repetitive DNA and Cytochrome C Oxidase I Sequence Analysis Reveal Differentiation among Sympatric Samples of Astyanax fasciatus (Characiformes, Characidae)

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

Physical mapping of 18S rDNA and heterochromatin in species of family Lygaeidae (Hemiptera: Heteroptera)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparative Chromosome Mapping of U2 snRNA and 5S rRNA Genes in Gymnotus Species (Gymnotiformes, Gymnotidae): Evolutionary Dynamics and Sex Chromosome Linkage in G. pantanal

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

Mapping of clay, iron oxide and adsorbed phosphate in Oxisols using diffuse reflectance spectroscopy

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

Chromosome mapping of retrotransposable elements Rex1 and Rex3 in Leporinus Spix, 1829 species (Characiformes: Anostomidae) and its relationships among heterochromatic segments and W sex chromosome

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