New Comparative Cytogenetic Data on Three Genera of Armored Catfishes of Ancistrini (Loricariidae: Hypostominae).

The karyotypes and other chromosomal markers of 4 catfish species, namely Lasiancistrus schomburgkii, Lasiancistrus sp., Araichthysloro, and Megalancistrus sp., members of a taxonomically complex and speciose tribe of catfishes Ancistrini, Hypostominae, were examined using conventional (Giemsa staining, Ag-NOR, and C-banding) and molecular cytogenetic protocols (FISH) and DNA barcoding. In L. schomburgkii, Lasiancistrus sp., and A.loro a diploid number 2n = 54 was observed, with karyotypes composed of 28m + 16sm + 10st, 36m + 12sm + 6st chromosomes, while Megalancistrus sp. had 2n = 52, with the karyotype composed of 28m + 16sm + 8st chromosomes. The Ag-NOR phenotypes were simple in all 4 species, which was confirmed by FISH with an 18S rDNA probe. However, the positive 5S rDNA sites varied among species: 2 chromosome pairs in L. schomburgkii, Lasiancistrus sp., and A. loro, and only 1 pair in Megalancistrus sp. The blocks of constitutive heterochromatin were poorly visible in the pericentromeric and telomeric regions of most chromosomes of the examined species by C-banding. The genetic distance analysis, based on mtDNA COI gene sequences (DNA barcoding), confirmed the species as 4 taxonomic units. Ours and other published data indicate that karyotype differentiation among Ancistrini is complex and divergent and indicates the occurrence of common chromosomal rearrangements, such as pericentric inversions conserving the diploid number, and other rearrangements that are more frequent in some genera, such as centric fusions in Ancistrus.

Mapping of the Retrotransposable Elements Rex1 and Rex3 in Chromosomes of Eigenmannia (Teleostei, Gymnotiformes, Sternopygidae).

Transposable elements constitute a remarkable fraction of the eukaryote genome and show particular capacity to move and insert in specific regions of the genome. This study identified the retrotransposable elements Rex1 and Rex3 in the genomes of 6 cytotypes of Eigenmannia. The sequences were isolated by PCR, sequenced and physically mapped in the chromosomes of these cytotypes, aiming to investigate the organization and distribution of these elements in this fish group, mainly in the sex chromosomes. The FISH physical mapping revealed that both Rex1 and Rex3 elements are dispersed in small clusters throughout the chromosomes of all cytotypes analyzed. However, conspicuous blocks occur in several samples, including an accentuated accumulation of the Rex3 element in X(1) and X(2) chromosomes of Eigenmannia sp. 2 and in the X chromosome of E. virescens. The accumulations are coincident with heterochromatin-rich regions, suggesting that Rex3 played a role in the differentiation process of the sex chromosomes.

Organization and Chromosomal Distribution of Histone Genes and Transposable Rex Elements in the Genome of Astyanax bockmanni (Teleostei, Characiformes).

An important feature of eukaryotic organisms is the number of different repetitive DNA sequences in their genome, a feature not observed in prokaryotes. These sequences are considered to be important components for understanding evolutionary mechanisms and the karyotypic differentiation processes. Thus, we aimed to physically map the histone genes and transposable elements of the Rex family in 6 fish populations of Astyanax bockmanni. FISH results using a histone H1 gene probe showed fluorescent clusters in 2 chromosome pairs in all 6 samples analyzed. In contrast, FISH with a histone H3 probe showed conspicuous blocks in 4 chromosomes in 5 of the 6 populations analyzed. The sixth population revealed 7 chromosomes marked with this probe. Probes for the transposable elements Rex1 and Rex6 showed small sites dispersed on most chromosomes of the 6 populations, and the Rex3 element is located in a big block concentrated in only 1 acrocentric chromosome of 2 populations. As for the other populations, a Rex3 probe showed large blocks in more than 1 chromosome. Fish from Alambari and Campo Novo Stream have Rex3 elements dispersed along most of the chromosomes. Additionally, the conspicuous signals of Rex1, Rex3, and Rex6 were identified in the acrocentric B microchromosome of A. bockmanni found only in individuals of the Alambari River. Thus, we believe that different mechanisms drive the spread of repetitive sequences among the populations analyzed, which appear to be organized differently in the genome of A. bockmanni. The presence of transposable elements in the B chromosome also suggests that these sequences could play a role in the origin and maintenance of the supernumerary element in the genome of this species.

Identification of novel and conserved microRNAs in Coffea canephora and Coffea arabica.

As microRNAs (miRNAs) are important regulators of many biological processes, a series of small RNAomes from plants have been produced in the last decade. However, miRNA data from several groups of plants are still lacking, including some economically important crops. Here microRNAs from Coffea canephora leaves were profiled and 58 unique sequences belonging to 33 families were found, including two novel microRNAs that have never been described before in plants. Some of the microRNA sequences were also identified in Coffea arabica that, together with C. canephora, correspond to the two major sources of coffee production in the world. The targets of almost all miRNAs were also predicted on coffee expressed sequences. This is the first report of novel miRNAs in the genus Coffea, and also the first in the plant order Gentianales. The data obtained establishes the basis for the understanding of the complex miRNA-target network on those two important crops.

Gymnotus paraguensis, a Good Example of Phenotypic Plasticity in the Pantanal Biome, Brazil.

Gymnotus is the most studied genus of the order Gymnotiformes, but the morphological similarities of the different species make it difficult to identify taxa reliably. The present study is a continuation of the ongoing research into the taxonomic diversity of the stocks of Gymnotus sold as live bait in the Pantanal, Brazil. These studies have been based on cytogenetic analyses, DNA barcoding, and the analysis of coloration patterns. The results of the cytogenetic analysis confirmed the presence of three distinct strains, recognized as Gymnotus paraguensis, G. sylvius, and G. pantanal. However, the results revealed that the molecular operational taxonomic units identified as G. paraguensis actually include a relatively diverse set of fish, separated by considerable genetic distances. As the G. paraguensis specimens also presented considerable variation in coloration patterns, further genetic diversity analyses were conducted on these individuals, to test the hypothesis that more than one species is present in this cytotaxonomic unit. The haplotype network revealed a regional pattern in the distribution of this species. The results indicate that the observed variation in coloration patterns is associated with a high degree of phenotypic plasticity in G. paraguensis. These findings emphasize the importance of using an integrative approach for a more accurate diagnosis of Gymnotus, in particular, the species marketed as live bait for the fisheries of the upper Paraguay River basin in the Brazilian Pantanal.

DNA Barcoding Reveals High Levels of Divergence among Mitochondrial Lineages of Brycon (Characiformes, Bryconidae).

Brycon is an important group of Neotropical fish and the principal genus of the family Bryconidae, with 44 valid species that are found in some Central American rivers and practically all the major hydrographic basins of South America. These fish are medium to large in size, migratory, omnivorous, important seed dispersers for riparian forests, and bioindicators of environmental quality, given that they are found preferentially in rivers with clean, well oxygenated water. Many Brycon species are important fishery resources and some are farmed. Morphological and molecular studies have nevertheless indicated that the group is not monophyletic and has a number of unresolved taxonomic problems. Given this, the present study aimed to identify the Molecular Operational Taxonomic Units (MOTUs) of the genus using the mitochondrial cytochrome c oxidase I (COI) gene, with analyses of genetics distance (NJ), maximum likelihood (ML), and Bayesian Inference (BI), combined with two different species delimitation approaches (GMYC and ABGD). The results indicate that at least 31 MOTUs exist within the 18 species identified a priori based on their morphology. Many of these lineages require further investigation for a more definitive classification.

Binary mixtures of ionic liquids-DMSO as solvents for the dissolution and derivatization of cellulose: Effects of alkyl and alkoxy side chains.

The efficiency of mixtures of ionic liquids (ILs) and molecular solvents in cellulose dissolution and derivatization depends on the structures of both components. We investigated the ILs 1-(1-butyl)-3-methylimidazolium acetate (C4MeImAc) and 1-(2-methoxyethyl)-3-methylimidazolium acetate (C3OMeImAc) and their solutions in dimethyl sulfoxide, DMSO, to assess the effect of presence of an ether linkage in the IL side-chain. Surprisingly, C4MeImAc-DMSO was more efficient than C3OMeImAc-DMSO for the dissolution and acylation of cellulose. We investigated both solvents using rheology, NMR spectroscopy, and solvatochromism. Mixtures of C3OMeImAc-DMSO are more viscous, less basic, and form weaker hydrogen bonds with cellobiose than C4MeImAc-DMSO. We attribute the lower efficiency of C3OMeImAc to "deactivation" of the ether oxygen and C2H of the imidazolium ring due to intramolecular hydrogen bonding. Using the corresponding ILs with C2CH3 instead of C2H, namely, 1-butyl-2,3-dimethylimidazolium acetate (C4Me2ImAc) and 1-(2-methoxyethyl)-2,3-dimethylimidazolium acetate (C3OMe2ImAc) increased the concentration of dissolved cellulose; without noticeable effect on biopolymer reactivity.

Type specimens and names assigned to Coprophanaeus (Megaphanaeus) d'Olsoufieff, 1924, the largest New World dung beetles (Coleoptera: Scarabaeidae: Phanaeini).

Currently 13 species-group names assigned to the subgenus Megaphanaeus of Coprophanaeus are deemed available (or 'potentially available'), four of which denote valid species. In the present work we review the nomenclatural history of those names and conclude that two of them, Scarabaeus satelles Lichtenstein, 1796 and Copris ajax Sturm, 1826, are unavailable. For the other 11 names, we found type specimens of five, Scarabaeus bellicosus Olivier, 1789, Copris ensifer Germar, 1821, Phanaeus septentrionalis Pêssoa, 1934, P. vicinus Martínez, 1944, and P. vicinus var. argentinus Martínez, 1944. Two lectotypes are designated, one for Copris ensifer and other for Phanaeus septentrionalis. We were unable to locate the type series of the four names described by Castelnau (1840), i.e. Phanaeus ducalis, P. sylvanus, P. heros and P. miles, and of P. bonariensis Gory, 1844 and Scarabaeus lancifer Linné, 1767. For the latter, based on some iconotypes, we found that its type series was composite, including specimens of two different Megaphanaeus species, and, in addition, it was mixed with Copris ensifer type series. In order to fix the name to a sole species, a neotype is designated for Scarabaeus lancifer. The history of the names are presented in detail, and the application of these names to species is briefly re-discussed.

Cellulose carboxylate/tosylate mixed esters: Synthesis, properties and shaping into microspheres.

Cellulose carboxylate/tosylate mixed esters (Cel-Carboxy/Ts) were synthesized with constant degree of tosylation, DSTs=0.98 and variable degree of acylation, DSCarboxy; acetate, butanoate, and hexanoate. The tosylate (Cel-Ts) was prepared by reacting cellulose with tosyl chloride in presence of trimethylamine. The mixed esters were obtained by reacting Cel-Ts with carboxylic acid anhydride. The dependence of the following on DSCarboxy was investigated: IR data, including νCO, νSO and peak area (CO); empirical polarity of the films, determined by an adsorbed perichromic dye. We employed these parameters to determine DSCarboxy. Relative to ester saponification, these spectroscopic methods are convenient, expedient, and require much less sample. Mixed esters prepared physically from cellulose tosylate and tosylate/acetate behave only qualitatively similar to (Cel-Carboxy/Ts). The mixed esters were dissolved in acetone and regenerated in water as homogeneous microspheres.

A single FTO gene variant rs9939609 is associated with body weight evolution in a multiethnic extremely obese population that underwent bariatric surgery.

OBJECTIVES: The rs9939609 single nucleotide polymorphism (SNP) in the fat mass and obesity-associated (FTO) gene is involved in obesity. Few studies have been conducted on patients who underwent bariatric surgery. The aim of this study was to evaluate the influence of FTO SNPs on body weight, body composition, and weight regain during a 60-mo follow-up period after bariatric surgery. METHODS: The rs9939609 was genotyped in 146 individuals using a real-time polymerase chain reaction TaqMan assay. Data for lifestyle, comorbidities, body weight, body mass index (BMI), excess weight loss (EWL), and body composition were obtained before and 6, 12, 18, 24, 36, 48, and 60 mo after surgery. Data were analyzed by comparing two groups of patients according to rs9939609 FTO gene polymorphism. Mixed-regression models were constructed to evaluate the dynamics of body weight, BMI, and EWL over time in female patients. RESULTS: No differences were observed between the groups during the first 24 mo after surgery. After 36, 48, and 60 mo, body weight, fat mass, and BMI were higher, whereas fat-free mass and EWL were lower in the FTO-SNP patient group. Weight regain was more frequent and occurred sooner in the FTO-SNP group. CONCLUSIONS: There is a different evolution of weight loss in obese carriers of the FTO gene variant rs9939609 after bariatric surgery. However, this pattern was evident at only 2 y postbariatric surgery, inducing a lower proportion of surgery success and a greater and earlier weight regain.

Comparative cytogenetics of Astyanax (Teleostei: Characidae) from the upper Paraguay basin

Astyanax is one of the most abundant and diverse taxa of fishes in the Neotropical region. In order to increase the amount of cytogenetic information for Astyanax as well as to exhibit data to subsidize future taxonomic studies, this work analyzed three species of Astyanax: two species are cryptic, and are here reported to live in syntopy (A. abramis and A. lacustris); the first karyotype description for A. pirapuan is also presented. Cytogenetic analyzes reveal a diploid number of 2n=50 chromosomes for three species, yet with differences in their karyotype morphology. The physical mapping of 18S rDNA showed up to thirteen sites in A. pirapuan and two in A. abramis and A. lacustris. The physical mapping of 5S rDNA has proven to be an effective marker for the characterization of species of Astyanax studied in this work.(AU)

Astyanax é um dos táxons mais representados e diversos na região Neotropical. Com o intuito de aumentar as informações citogenéticas para Astyanax e apresentar dados que possam subsidiar estudos taxonômicos futuros, este trabalho traz uma análise citogenética de três espécies de Astyanax: duas espécies consideradas crípticas, aqui reportadas em sintopia (A. abramis e A. lacustris) e a primeira descrição cariotípica de A. pirapuan. As análises citogenéticas revelaram 2n=50 cromossomos para as três espécies, com diferença na morfologia cariotípica de cada uma. Foram observados apenas dois sítios de rDNA 18S em A. abramis e A. lacustris e até 13 para A. pirapuan. O mapeamento físico do rDNA 5S se mostrou como um marcador efetivo para a caracterização das espécies de Astyanax abordadas neste estudo.(AU)

Spectroscopic characterization of oligoaniline microspheres obtained by an aniline-persulfate approach.

This paper investigates the structure of the products obtained from the polymerization of aniline with ammonium persulfate in a citrate/phosphate buffer solution at pH 3 by resonance Raman, NMR, FTIR, and UV-vis-NIR spectroscopies. All the spectroscopic data showed that the major product presented segments that were formed by a 1,4-Michael reaction between aniline and p-benzoquinone monoimine, ruling out the formation of polyazane structure that has been recently proposed. The characterization of samples obtained at different stages of the reaction indicated that, as the reaction progressed, phenazine units were formed and 1,4-Michael-type adducts were hydrolyzed/oxidized to yield benzoquinone. Raman mapping data suggested that phenazine-like segments could be related to the formation of the microspheres morphology.

Distributions and phylogeographic data of rheophilic freshwater fishes provide evidences on the geographic extension of a central-brazilian amazonian palaeoplateau in the area of the present day Pantanal Wetland

The analysis of the distribution patterns presented by examples of freshwater fishes restricted to headwater habitat: the anostomid Leporinus octomaculatus, the characins Jubiaba acanthogaster, Oligosarcus perdido, Moenkhausia cosmops, Knodus chapadae, Planaltina sp., the loricariid Hypostomus cochliodon, and the auchenipterid Centromochlus sp. provided evidences of a relatively recent shared history between the highlands of the upper rio Paraguay and adjoining upland drainage basins. Restricted to headwater of the uplands in the upper rio Paraguay and adjoining basins, these species provide biological evidence of the former extension of the central Brazilian plateau before the origin of the Pantanal Wetland. Disjunction took place due to an ecological barrier to these rheophilic taxa represented tectonic subsidence related to the origin of the Pantanal Wetland. Molecular analysis of Jubiaba acanthogaster revealed that the sample from the upper rio Xingu basin are the sister-group of a clade that includes samples from the upper rio Arinos (upper rio Tapajós) plus the upper rio Paraguay basin, supporting the assumption that the origin of the upper rio Paraguay basin causing vicariance between this basin and the upper rio Tapajós is the least vicariant event in the evolutionary history of the group.

A análise do padrão de distribuição apresentado por exemplos de peixes de água doce neotropicais restritos à habitats reofílicos de cabeceira: o anostomídeo Leporinus octomaculatus, os caracídeos Jubiaba acanthogaster, Oligosarcus perdido, Moenkhausia cosmops, Knodus chapadae, Planaltina sp., o loricariídeo Hypostomus cochliodon e o auquenipterídeo Centromochlus sp. fornecem evidências de uma história compartilhada relativamente recente entre as terras altas do alto rio Paraguai e bacias de terras altas vizinhas. Restritas às cabeceiras das áreas altas nas bacias do alto rio Paraguai e bacias vizinhas, estas espécies fornecem evidências biológicas da pretérita extensão do Planalto Central Brasileiro anteriormente a origem tectônica da planície alagável do Pantanal. Disjunções ocorreram devido a barreira ecológica para estes taxons reofílicos representada pela subsidência tectônica associada à origem do Pantanal. A análise molecular de Jupiaba acanthogaster revelou que amostras da bacia do alto rio Xingu consistem no grupo-irmão de um clado mais inclusivo que inclui amostras do alto rio Arinos (alto rio Tapajós) mais o alto rio Paraguai, suportando a suposição de que a origem do alto rio Paraguai causou vicariância entre esta bacia e o alto rio Tapajós no último evento vicariante na história evolutiva do grupo.

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)

Lutjanidae, commonly known as snappers, includes 105 species, grouped in four subfamilies. In spite of the high number of species and of its worldwide distribution, the family has been little investigated and the phylogenetic relationships among some of its genera and species are still cause for debate. Only a small number of the species has been cytogenetically analysed. This study reports the first description of the karyotype of Rhomboplites aurorubens as well as data concerning the distribution of the constitutive heterochromatin and the location of the 18S rRNA and the 5S rRNA genes. Specimens of Ocyurus chrysurus from Venezuela were also investigated for the same cytogenetic features. Both species have a 48 uniarmed karyotype, but R. aurorubens has a single subtelocentric chromosome pair, the smallest of the chromosome complement, among the other acrocentric chromosomes. The C-positive heterochromatin is limited to the pericentromeric regions of all chromosomes. Both species show a single chromosome pair bearing the Nucleolus Organizer Regions, but NORs are differently located, in a terminal position on the short arms of the smallest chromosomes in R. aurorubens and in a paracentromeric position in a chromosome pair of large size in O. chrysurus. In O. chrysurus, the 5S rDNA gene cluster is located on a medium-sized chromosome pair, whereas in R. aurorubens it is syntenic with the 18S rDNA gene cluster on chromosome pair number 24. The obtained cytogenetic data, along with previous cytogenetic, morphological and molecular data for the family, reinforce the proposal to synonymize genus Ocyurus with Lutjanus. A review of Lutjanidae cytogenetics is also included.

Lutjanidae, comumente conhecidos como snappers, inclui 105 espécies, reunidas em quatro subfamílias. A despeito do grande número de espécies e de sua distribuição mundial, a família tem sido pouco estudada e as relações filogenéticas entre alguns de seus gêneros e espécies ainda é motivo de debates. Apenas um pequeno número de espécies foi citogeneticamente analisada. Esse estudo apresenta a primeira descrição do cariótipo de Rhomboplites aurorubens assim como dados relativos à distribuição de heterocromatina constitutiva e localização dos genes 18S rRNA e 5S rRNA. Espécimes de Ocyurus chrysurus da Venezuela foram também analisados quanto às mesmas características citogenéticas. Ambas as espécies têm cariótipos compostos de 48 cromossomos com um único braço, entretanto R. aurorubens tem um único par de cromossomos subtelocêntrico, o menor do complemento cromossômico, entre os outros cromossomos acrocêntricos. A heterocromatina C-positiva é limitada à região pericentromérica de todos os cromossomos. Ambas as species apresentam um único par com Regiões Organizadoras de Nucléolo, mas as RONs são localizadas em posições diferentes, em posição terminal no braço curto dos menores cromossomos de R. aurorubens e em posição paracentromérica no braço longo de um par de cromossomos grandes de O. chrysurus. Em O. chrysurus, os genes 5S rDNA estão localizados em um par de cromossomos de tamanho médio, enquanto em R. aurorubens eles são sintenicamente localizados com os genes 18S rDNA no par de cromossomos número 24. Os dados citogenéticos obtidos, junto com os dados morfológicos e moleculares disponíveis para a família reforçam a proposta de sinonimizar o gênero Ocyurus com Lutjanus. Uma revisão da citogenética dos Lutjanidae é também apresentada