Search tips
Search criteria

Results 1-25 (39)

Clipboard (0)

Select a Filter Below

Year of Publication
1.  Production, crystallization and preliminary crystallographic analysis of Allochromatium vinosum thiosulfate dehydrogenase TsdA, an unusual acidophilic c-type cytochrome 
The thiosulfate dehydrogenase TsdA from A. vinosum was recombinantly expressed, purified and crystallized. The crystals belonged to space group C2, with unit-cell parameters a = 79.2, b = 69.9, c = 57.9 Å, β = 129.3°, and diffracted to a resolution of 1.98 Å.
The ability to perform the very simple oxidation of two molecules of thiosulfate to tetrathionate is widespread among prokaryotes. Despite the prevalent occurrence of tetrathionate formation and its well documented significance within the sulfur cycle, little is known about the enzymes that catalyze the oxidative condensation of two thiosulfate anions. To fill this gap, the thiosulfate dehydrogenase (TsdA) enzyme from the purple sulfur bacterium Allochromatium vinosum was recombinantly expressed in Escherichia coli, purified and crystallized, and a crystallographic data set was collected. The crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 79.2, b = 69.9, c = 57.9 Å, β = 129.3°, contained one monomer per asymmetric unit and diffracted to a resolution of 1.98 Å.
PMCID: PMC4188095  PMID: 25286955
thiosulfate dehydrogenase; Allochromatium vinosum; c-type cytochrome; sulfur metabolism
2.  Lipid-laden cells differentially distributed in the aging brain are functionally active and correspond to distinct phenotypes 
Scientific Reports  2016;6:23795.
We characterized cerebral Oil Red O-positive lipid-laden cells (LLC) of aging mice evaluating their distribution, morphology, density, functional activities and inflammatory phenotype. We identified LLC in meningeal, cortical and neurogenic brain regions. The density of cerebral LLC increased with age. LLC presenting small lipid droplets were visualized adjacent to blood vessels or deeper in the brain cortical and striatal parenchyma of aging mice. LLC with larger droplets were asymmetrically distributed in the cerebral ventricle walls, mainly located in the lateral wall. We also found that LLC in the subventricular region co-expressed beclin-1 or LC3, markers for autophagosome or autophagolysosome formation, and perilipin (PLIN), a lipid droplet-associated protein, suggesting lipophagic activity. Some cerebral LLC exhibited β galactosidase activity indicating a senescence phenotype. Moreover, we detected production of the pro-inflammatory cytokine TNF-α in cortical PLIN+ LLC. Some cortical NeuN+ neurons, GFAP+ glia limitans astrocytes, Iba-1+ microglia and S100β+ ependymal cells expressed PLIN in the aging brain. Our findings suggest that cerebral LLC exhibit distinct cellular phenotypes and may participate in the age-associated neuroinflammatory processes.
PMCID: PMC4814830  PMID: 27029648
3.  Development and characterization of polymorphic microsatellite loci for spiny-footed lizards, Acanthodactylusscutellatus group (Reptilia, Lacertidae) from arid regions 
BMC Research Notes  2015;8:794.
Spiny-footed lizards constitute a diverse but scarcely studied genus. Microsatellite markers would help increasing the knowledge about species boundaries, patterns of genetic diversity and structure, and gene flow dynamics. We developed a set of 22 polymorphic microsatellite loci for cross-species amplification in three taxa belonging to the Acanthodactylus scutellatus species group, A. aureus, A. dumerili/A. senegalensis and A. longipes, and tested the same markers in two other members of the group, A. scutellatus and A. taghitensis.
Amplifications in A. aureus, A. longipes and A. dumerili/A.senegalensis were successful, with markers exhibiting a number of alleles varying between 1 and 19. Expected and observed heterozygosity ranged, respectively, between 0.046–0.893 and 0.048–1.000. Moreover, 17 and 16 loci were successfully amplified in A. scutellatus and A. taghitensis, respectively.
These markers are provided as reliable genetic tools to use in future evolutionary, behavioural and conservation studies involving species from the A. scutellatus group.
PMCID: PMC4683941  PMID: 26681434
Cross-species amplification; Nuclear markers; Population genetics; Sahara-Sahel
5.  Molecular and Morphological Differentiation of Common Dolphins (Delphinus sp.) in the Southwestern Atlantic: Testing the Two Species Hypothesis in Sympatry 
PLoS ONE  2015;10(11):e0140251.
The taxonomy of common dolphins (Delphinus sp.) has always been controversial, with over twenty described species since the original description of the type species of the genus (Delphinus delphis Linnaeus, 1758). Two species and four subspecies are currently accepted, but recent molecular data have challenged this view. In this study we investigated the molecular taxonomy of common dolphins through analyses of cytochrome b sequences of 297 individuals from most of their distribution. We included 37 novel sequences from the Southwestern Atlantic Ocean, a region where the short- and long-beaked morphotypes occur in sympatry, but which had not been well sampled before. Skulls of individuals from the Southwestern Atlantic were measured to test the validity of the rostral index as a diagnostic character and confirmed the presence of the two morphotypes in our genetic sample. Our genetic results show that all common dolphins in the Atlantic Ocean belong to a single species, Delphinus delphis. According to genetic data, the species Delphinus capensis is invalid. Long-beaked common dolphins from the Northeastern Pacific Ocean may constitute a different species. Our conclusions prompt the need for revision of currently accepted common dolphin species and subspecies and of Delphinus delphis distribution.
PMCID: PMC4641715  PMID: 26559411
7.  Deep brain stimulation induces antiapoptotic and anti-inflammatory effects in epileptic rats 
Status epilepticus (SE) is a severe condition that may lead to hippocampal cell loss and epileptogenesis. Some of the mechanisms associated with SE-induced cell death are excitotoxicity, neuroinflammation, and apoptosis.
The objective of the present study is to test the hypothesis that DBS has anti-inflammatory and antiapoptotic effects when applied during SE.
Rats undergoing pilocarpine-induced SE were treated with anterior thalamic nucleus (AN) deep brain stimulation (DBS). Inflammatory changes and caspase 3 activity were measured within 1 week of treatment.
In pilocarpine-treated rats, DBS countered the significant increase in hippocampal caspase 3 activity and interleukin-6 (IL-6) levels that follows SE but had no effect on tumor necrosis factor α (TNFα).
DBS has anti-inflammatory and antiapoptotic effects when given to animals undergoing status.
Electronic supplementary material
The online version of this article (doi:10.1186/s12974-015-0384-7) contains supplementary material, which is available to authorized users.
PMCID: PMC4558969  PMID: 26337974
Anterior thalamic nucleus; Thalamus; Seizures; Deep brain stimulation; Epilepsy; Apoptosis; Neuroprotection; Caspase
8.  Chick embryo xenograft model reveals a novel perineural niche for human adipose-derived stromal cells 
Biology Open  2015;4(9):1180-1193.
Human adipose-derived stromal cells (hADSC) are a heterogeneous cell population that contains adult multipotent stem cells. Although it is well established that hADSC have skeletal potential in vivo in adult organisms, in vitro assays suggest further differentiation capacity, such as into glia. Thus, we propose that grafting hADSC into the embryo can provide them with a much more instructive microenvironment, allowing the human cells to adopt diverse fates or niches. Here, hADSC spheroids were grafted into either the presumptive presomitic mesoderm or the first branchial arch (BA1) regions of chick embryos. Cells were identified without previous manipulations via human-specific Alu probes, which allows efficient long-term tracing of heterogeneous primary cultures. When grafted into the trunk, in contrast to previous studies, hADSC were not found in chondrogenic or osteogenic territories up to E8. Surprisingly, 82.5% of the hADSC were associated with HNK1+ tissues, such as peripheral nerves. Human skin fibroblasts showed a smaller tropism for nerves. In line with other studies, hADSC also adopted perivascular locations. When grafted into the presumptive BA1, 74.6% of the cells were in the outflow tract, the final goal of cardiac neural crest cells, and were also associated with peripheral nerves. This is the first study showing that hADSC could adopt a perineural niche in vivo and were able to recognize cues for neural crest cell migration of the host. Therefore, we propose that xenografts of human cells into chick embryos can reveal novel behaviors of heterogeneous cell populations, such as response to migration cues.
PMCID: PMC4582113  PMID: 26319582
Adipose-derived stromal cell; Alu; Chick embryo; Niche; Stem cell; Xenograft
9.  Expression Analysis of Genes Involved in the RB/E2F Pathway in Astrocytic Tumors 
PLoS ONE  2015;10(8):e0137259.
Astrocytic gliomas, which are derived from glial cells, are considered the most common primary neoplasias of the central nervous system (CNS) and are histologically classified as low grade (I and II) or high grade (III and IV). Recent studies have shown that astrocytoma formation is the result of the deregulation of several pathways, including the RB/E2F pathway, which is commonly deregulated in various human cancers via genetic or epigenetic mechanisms. On the basis of the assumption that the study of the mechanisms controlling the INK4/ARF locus can help elucidate the molecular pathogenesis of astrocytic tumors, identify diagnostic and prognostic markers, and help select appropriate clinical treatments, the present study aimed to evaluate and compare methylation patterns using bisulfite sequencing PCR and evaluate the gene expression profile using real-time PCR in the genes CDKN2A, CDKN2B, CDC6, Bmi-1, CCND1, and RB1 in astrocytic tumors. Our results indicate that all the evaluated genes are not methylated independent of the tumor grade. However, the real-time PCR results indicate that these genes undergo progressive deregulation as a function of the tumor grade. In addition, the genes CDKN2A, CDKN2B, and RB1 were underexpressed, whereas CDC6, Bmi-1, and CCND1 were overexpressed; the increase in gene expression was significantly associated with decreased patient survival. Therefore, we propose that the evaluation of the expression levels of the genes involved in the RB/E2F pathway can be used in the monitoring of patients with astrocytomas in clinical practice and for the prognostic indication of disease progression.
PMCID: PMC4552853  PMID: 26317630
10.  Relationship between menopause and periodontal disease: a cross-sectional study in a Portuguese population 
Background: Menopause is associated with important systemic and oral changes. Many researchers have tried to evaluate the influence of hormonal changes associated with menopause in the periodontium, however results are contradictory. Objective: Evaluate the possible effects of menopause on the severity of periodontal disease and tooth loss, by considering several general, oral and periodontal parameters. Methods: 102 women with chronic periodontitis, and at least six teeth, were divided into two groups: a study group (SG) consisting of 68 menopausal women and a control group (CG) consisting of 34 premenopausal women. The participants had extensive anamnesis, made by a single senior periodontologist, which collected demographic data, medical and gynaecological history and habits. Additionally, oral and periodontal parameters including: number of teeth, plaque index, presence of calculi, probing depth, bleeding on probing, gingival recession and attachment loss were recorded. The following statistical tests were used: Chi-square, Fisher’s t-test for independent samples, non-parametric Wilcoxon-Mann-Whitney, and linear multiple regression. Results: The number of teeth was significantly lower in postmenopausal women (SG 10.8 ± 5.9, CG 6.8 ± 4.6), however, after adjusting for age, smoking and plaque index, the difference was no longer statistically significant (P=0.169). The attachment loss was slightly higher in the study group, although the difference is not significant (SG 4.31 ± 1.08, CG 4.05 ± 1.28). Conclusions: Menopause does not appear to significantly influence the severity of periodontal disease and tooth loss. Other factors may exert a greater influence on the progression of periodontal disease rather than menopause itself.
PMCID: PMC4565340  PMID: 26379957
Periodontal disease; menopause; osteoporosis; oestrogen
11.  Effect of Cinnamon Tea on Postprandial Glucose Concentration 
Journal of Diabetes Research  2015;2015:913651.
Glycaemic control, in particular at postprandial period, has a key role in prevention of different diseases, including diabetes and cardiovascular events. Previous studies suggest that postprandial high blood glucose levels (BGL) can lead to an oxidative stress status, which is associated with metabolic alterations. Cinnamon powder has demonstrated a beneficial effect on postprandial glucose homeostasis in animals and human models. The purpose of this study is to investigate the effect of cinnamon tea (C. burmannii) on postprandial capillary blood glucose level on nondiabetic adults. Participants were given oral glucose tolerance test either with or without cinnamon tea in a randomized clinical trial. The data revealed that cinnamon tea administration slightly decreased postprandial BGL. Cinnamon tea ingestion also results in a significantly lower postprandial maximum glucose concentration and variation of maximum glucose concentration (p < 0.05). Chemical analysis showed that cinnamon tea has a high antioxidant capacity, which may be due to its polyphenol content. The present study provides evidence that cinnamon tea, obtained from C. burmannii, could be beneficial for controlling glucose metabolism in nondiabetic adults during postprandial period.
PMCID: PMC4516848  PMID: 26258147
12.  Primigravida with Bernard-Soulier Syndrome: a case report 
BMC Research Notes  2015;8:178.
Bernard-Soulier Syndrome is a rare congenital bleeding disorder, mainly inherited in an autosomal recessive pattern. It is characterized by a genetic defect on one of the four genes encoding the subunits of the transmembrane protein complex GPIb-V-IX, physiologically expressed only in platelets. The exact phenotype varies widely from individual to individual depending on the particular mutation presented. Currently, there is no consensus about ideal management of affected pregnant women, in face of the scarcity of cases.
Case presentation
We report on a 28-year-old Black Brazilian primigravida who was referred to our maternity hospital, a tertiary care center, for decision about the most adequate mode of delivery. She was admitted with a platelet count of 43.000 plt/μL, and hemoglobin of 13.6 g/dL. Platelet transfusion was regarded as a necessary prophylactic measure prior to delivery. Ten units of random donor platelets were administered on the course of three days, after which the patient was submitted to an elective cesarean section delivery under general anesthesia at 40 weeks of gestational age. A healthy male baby with a normal birthweight of 3.615 kg was delivered. After the delivery, the mother’s state continued being assessed daily, with special attention taken to lochia and surgical wound healing. At one week postpartum, a complete blood count revealed a platelet count of 41.000 plt/μL, and hemoglobin of 13.3 g/dL. As there were no signs of neither evident nor occult hemorrhage, and surgical wound was healing accordingly, the patient was discharged, after being oriented about bleeding preventive measures.
The peripartum period is regarded as the most crucial moment of pregnancy in women with Bernard-Soulier Syndrome, hence the importance of a judiciously planned mode of delivery, and of careful prophylaxis against bleeding beforehand. Furthermore, absence of complications during the peripartum period does not predict how the woman will do subsequently. Strict vigilance is warranted at least until six weeks postpartum, due to the virtual risk of secondary postpartum hemorrhage.
PMCID: PMC4434533  PMID: 25928053
Bernard-Soulier syndrome; Blood coagulation disorders; Blood platelet disorders; Platelet transfusion; Pregnancy complications, hematologic
13.  Histomorphometric Evaluation of the Small Coronary Arteries in Rats Exposed to Industrial Noise 
Morphological changes induced by industrial noise (IN) have been experimentally observed in several organs. Histological observations of the coronary arteries showed prominent perivascular tissue and fibrosis among IN-exposed rats. The effects on the small arteries are unknown. Objective: To evaluate the histomorphometric changes induced by IN on rat heart small arteries. Methods: Twenty Wistar rats exposed to IN during a maximum period of seven months and 20 age-matched controls were studied. Hearts were transversely sectioned from ventricular apex to atria and a mid-ventricular fragment was selected for analysis. The histological images were obtained with an optical microscope using 400× magnifications. A total of 634 arterial vessels (298 IN-exposed and 336 controls) were selected. The mean lumen-to-vessel wall (L/W) and mean vessel wall-to-perivascular tissue (W/P) ratios were calculated using image J software. Results: There were no differences between exposed and control animals in their L/W ratios (p = 0.687) and time variations in this ratio were non-significant (p = 0.110). In contrast, exposed animals showed lower W/P ratios than control animals (p < 0.001), with significant time variations (p = 0.004). Conclusions: Industrial noise induced an increase in the perivascular tissue of rat small coronary arteries, with significant development of periarterial fibrosis.
PMCID: PMC4463634  PMID: 25946344
industrial noise; small coronary arteries; low-frequency noise
14.  Overlooked Mountain Rock Pools in Deserts Are Critical Local Hotspots of Biodiversity 
PLoS ONE  2015;10(2):e0118367.
The world is undergoing exceptional biodiversity loss. Most conservation efforts target biodiversity hotspots at large scales. Such approach overlooks small-sized local hotspots, which may be rich in endemic and highly threatened species. We explore the importance of mountain rock pools (gueltas) as local biodiversity hotspots in the Sahara-Sahel. Specifically, we considered how many vertebrates (total and endemics) use gueltas, what factors predict species richness, and which gueltas are of most priority for conservation. We expected to provide management recommendations, improve local biodiversity conservation, and simultaneously contribute with a framework for future enhancement of local communities’ economy. The identification of local hotspots of biodiversity is important for revaluating global conservation priorities.
Methodology/Principal Findings
We quantified the number of vertebrate species from each taxonomic group and endemics present in 69 gueltas in Mauritania, then compared these with species present in a surrounding area and recorded in the country. We evaluated the predictors of species number’s present in each guelta through a multiple regression model. We ranked gueltas by their priority for conservation taking into account the percentage of endemics and threats to each guelta. Within a mere aggregate extent of 43 ha, gueltas hold about 32% and 78% of the total taxa analysed and endemics of Mauritania, respectively. The number of species present in each guelta increased with the primary productivity and area of gueltas and occurrence of permanent water. Droughts and human activities threaten gueltas, while 64% of them are currently unprotected.
Gueltas are crucial for local biodiversity conservation and human activities. They require urgent management plans in Mauritania’s mountains. They could provide refugia under climate change being important for long-term conservation of Sahara-Sahel biodiversity. Given their disproportional importance in relation to their size, they are local hotspots of biodiversity deserving global attention.
PMCID: PMC4340953  PMID: 25714751
15.  Arthritis Induces Early Bone High Turnover, Structural Degradation and Mechanical Weakness 
PLoS ONE  2015;10(1):e0117100.
We have previously found in the chronic SKG mouse model of arthritis that long standing (5 and 8 months) inflammation directly leads to high collagen bone turnover, disorganization of the collagen network, disturbed bone microstructure and degradation of bone biomechanical properties. The main goal of the present work was to study the effects of the first days of the inflammatory process on the microarchitecture and mechanical properties of bone.
Twenty eight Wistar adjuvant-induced arthritis (AIA) rats were monitored during 22 days after disease induction for the inflammatory score, ankle perimeter and body weight. Healthy non-arthritic rats were used as controls for compar-ison. After 22 days of disease progression rats were sacrificed and bone samples were collected for histomorphometrical, energy dispersive X-ray spectroscopical analysis and 3-point bending. Blood samples were also collected for bone turnover markers.
AIA rats had an increased bone turnover (as inferred from increased P1NP and CTX1, p = 0.0010 and p = 0.0002, respectively) and this was paralleled by a decreased mineral content (calcium p = 0.0046 and phos-phorus p = 0.0046). Histomorphometry showed a lower trabecular thickness (p = 0.0002) and bone volume (p = 0.0003) and higher trabecular sepa-ration (p = 0.0009) in the arthritic group as compared with controls. In addition, bone mechanical tests showed evidence of fragility as depicted by diminished values of yield stress and ultimate fracture point (p = 0.0061 and p = 0.0279, re-spectively) in the arthritic group.
We have shown in an AIA rat model that arthritis induc-es early bone high turnover, structural degradation, mineral loss and mechanical weak-ness.
PMCID: PMC4305284  PMID: 25617902
16.  Taxonomic and ecological discrimination of Fagaceae species based on internal transcribed spacer polymerase chain reaction–restriction fragment length polymorphism 
AoB Plants  2014;7:plu079.
In 30 Fagaceae individuals from the Castanea, Fagus and Quercus genera, the internal transcribed spacer region (ITS) of the ribosomal DNA (rDNA) was amplified and digested with four restriction enzymes (HaeIII, HpaII, Sau96I, and TaqI), producing ITS PCR-RFLP markers. This technique allowed the discrimination of the Fagaceae species according to genus, infrageneric group and ecological area. This study constitutes the first application of the alternative co-dominant marker system ITS PCR-RFLP in Fagaceae species and proved to be highly suitable for taxonomic and ecological discrimination, constituting a useful molecular tool for taxonomists and forestry researchers.
The internal transcribed spacer (ITS) of ribosomal DNA has been used to confirm taxonomic classifications and define phylogenies in several plant species following sequencing or polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) techniques. In this study, co-dominant ITS PCR–RFLP molecular markers were produced in 30 Fagaceae individuals belonging to the Castanea, Fagus and Quercus genera in order to assess the potential of this technique for taxonomic discrimination and determination of phylogenies. The complete ITS region (ITS1-5.8S rRNA-ITS2) was amplified in most of the Fagaceae individuals as a single fragment of ∼700 bp. The ITS amplified products were digested with nine restriction enzymes, but only four (HaeIII, HpaII, TaqI and Sau96I) produced polymorphic/discriminative patterns. The total expected heterozygosity (HE) was 20.31 % and the gene diversity (I), 32.97 %. The ITS polymorphism was higher within the Quercus genus (85.3 %). The ITS PCR–RFLP markers clustered the Fagaceae species according to genus or infrageneric group (in the case of Quercus sp. individuals). Five oaks did not cluster in line with the adopted infrageneric classification, but three of these were grouped according to their actual ecological distributions. The ITS PCR–RFLP markers indicated their potential for phylogenetic studies since all Fagaceae individuals were discriminated according to genus, and most of the oaks were clustered according to infrageneric group or ecological area.
PMCID: PMC4294445  PMID: 25429047
Castanea; Fagus; internal transcribed spacer (ITS); Quercus; restriction fragment length polymorphism (RFLP).
17.  Industrial Noise and Tooth Wear - Experimental Study 
Tooth wear is a complex multifactorial process that involves the loss of hard dental tissue. Parafunctional habits have been mentioned as a self-destructive process caused by stress, which results in hyperactivity of masticatory muscles. Stress manifests itself through teeth grinding, leading to progressive teeth wear. The effects of continuous exposure to industrial noise, a “stressor” agent, cannot be ignored and its effects on the teeth must be evaluated.
Aims: The aim of this study was to ascertain the effects of industrial noise on dental wear over time, by identifying and quantifying crown area loss.
Material and Methods: 39 Wistar rats were used. Thirty rats were divided in 3 experimental groups of 10 animals each. Animals were exposed to industrial noise, rich in LFN components, for 1, 4 and 7 months, with an average weekly exposure of 40 hours (8h/day, 5 days/week with the weekends in silence). The remaining 9 animals were kept in silence. The areas of the three main cusps of the molars were measured under light microscopy.
Statistical analysis used: A two-way ANOVA model was applied at significance level of 5%.
Results: The average area of the molar cusps was significantly different between exposed and non-exposed animals. The most remarkable differences occurred between month 1 and 4. The total crown loss from month 1 to month 7 was 17.3% in the control group, and 46.5% in the exposed group, and the differences between these variations were significant (p<0.001).
Conclusions: Our data suggest that industrial noise is an important factor in the pathogenesis of tooth wear.
PMCID: PMC4366631  PMID: 25798052
tooth wear; industrial noise; low frequency noise; stress; parafunctional habits; bruxism.
18.  Noise rich in low frequency components, a new comorbidity for periodontal disease? An experimental study 
Exposure to noise rich in low frequency components induces abnormal proliferation of extracellular matrix and collagens. The previous studies have shown alterations in the periodontium of both humans and animals. Our objective was the evaluation of collagens I, IV and V of the periodontium of Wistar rats exposed to noise rich in low frequency components.
Materials and Methods:
5 groups (each with 10 animals) were exposed to continuous low frequency noise (LFN). The LFN, from previously recorded white noise, frequency filtered and amplified, was applied in growing periods of 1, 3, 5, 9 and 13 weeks, in order to characterize the alterations with exposure time. A control group of ten animals was kept in silence. These animals were used in groups of 2 as aged-matched controls. After exposure, sections were obtained including teeth, alveolar bone and periodontium and observed after immunollabeling for collagens I, IV and V.
A significant increase in collagen I was observed in exposed groups (P < 0.001) (Kruskal-Wallis test). Post-hoc comparisons (Mann-Whitney test with Bonferroni correction) showed an increase in collagen I in animals exposed for 3 weeks or more (P < 0.001). The same test was applied to collagen V where significant differences were found when comparing control and exposed groups (P ≤ 0.004). The t-test for independent samples was applied to collagen type IV where no significant differences were found (P = 0.410), when comparing to the control group.
As in other organs, we can observe fibrosis and the newly formed collagen is likely to be “nonfunctional”, which could have clinical impact.
Noise may constitute a new comorbidity for periodontal disease.
PMCID: PMC4158595  PMID: 25210268
Fibrosis; low frequency noise; periodontal disease; periodontium
19.  Should I Stay or Should I Go? Dispersal and Population Structure in Small, Isolated Desert Populations of West African Crocodiles 
PLoS ONE  2014;9(4):e94626.
The maintenance of both spatial and genetic connectivity is paramount to the long-term persistence of small, isolated populations living in environments with extreme climates. We aim to identify the distribution of genetic diversity and assess population sub-structuring and dispersal across dwarfed desert populations of Crocodylus suchus, which occur in isolated groups, usually less than five individuals, along the mountains of Mauritania (West Africa). We used both invasive and non-invasive sampling methods and a combination of mitochondrial DNA (12 S and ND4) and microsatellite markers (32 loci and a subset of 12 loci). Our results showed high genetic differentiation and geographic structure in Mauritanian populations of C. suchus. We identified a metapopulation system acting within four river sub-basins (high gene flow and absence of genetic structure) and considerable genetic differentiation between sub-basins (FST range: 0.12–0.24) with rare dispersal events. Effective population sizes tend to be low within sub-basins while genetic diversity is maintained. Our study suggests that hydrographic networks (temporal connections along seasonal rivers during rainy periods) allow C. suchus to disperse and maintain metapopulation dynamics within sub-basins, which attenuate the loss of genetic diversity and the risk of extinction. We highlight the need of hydrographic conservation to protect vulnerable crocodiles isolated in small water bodies. We propose C. suchus as an umbrella species in Mauritania based on ecological affinities shared with other water-dependent species in desert environments.
PMCID: PMC3989217  PMID: 24740183
20.  Large Spatial Scale of the Phenotype-Environment Color Matching in Two Cryptic Species of African Desert Jerboas (Dipodidae: Jaculus) 
PLoS ONE  2014;9(4):e94342.
We tested the camouflage hypothesis, or the linkage between animal (Saharan rodent) and habitat coloration, on the largest geographical scale yet conducted. We aimed to determine whether phenotypic variation is explained by micro-habitat variation and/or genetic polymorphism to determine 1) the strength of linkage between fur color and local substrate color, and 2) the divergence in fur coloration between two genetic clades, representing cryptic species, throughout the complete range of the African desert jerboas (Jaculus jaculus). We used a combination of museum and field-collected specimens, remote sensing tools, satellite and digital photography and molecular genetic and phylogenetic methods to investigate the above hypotheses. Along with showing that the two divergent genetic clades of jerboas occur sympatrically throughout their African distribution, we showed significant covariation between dorsal fur coloration of the animals and the color of their habitat. We also described significant phenotypic divergence in fur color, consistent with genetic divergence between the sympatric clades. The linkage between environment and phenotype supports the idea that the selection promoting cryptic coloration is persistent in contemporary populations of jerboas, however the phenotypic divergence indicates that it has different strengths (or optima) in the two clades. The mosaic distribution of micro-habitats occupied by geographically sympatric clades suggests that it may influence both ecological and evolutionary dynamics between these two cryptic species.
PMCID: PMC3979769  PMID: 24714509
21.  Population Structure of the Endangered Franciscana Dolphin (Pontoporia blainvillei): Reassessing Management Units 
PLoS ONE  2014;9(1):e85633.
Franciscanas are the most endangered dolphins in the Southwestern Atlantic. Due to their coastal and estuarine habits, franciscanas suffer from extensive fisheries bycatch, as well as from habitat loss and degradation. Four Franciscana Management Areas (FMA), proposed based on biology, demography, morphology and genetic data, were incorporated into management planning and in the delineation of research efforts. We re-evaluated that proposal through the analysis of control region sequences from franciscanas throughout their distribution range (N = 162), including novel sequences from the northern limit of the species and two other previously unsampled localities in Brazil. A deep evolutionary break was observed between franciscanas from the northern and southern portions of the species distribution, indicating that they must be managed as two Evolutionarily Significant Units (ESU). Furthermore, additional FMAs should be recognised to accommodate the genetic differentiation found in each ESU. These results have immediate consequences for the conservation and management of this endangered species.
PMCID: PMC3908959  PMID: 24497928
22.  Trophic Relationships and Habitat Preferences of Delphinids from the Southeastern Brazilian Coast Determined by Carbon and Nitrogen Stable Isotope Composition 
PLoS ONE  2013;8(12):e82205.
To investigate the foraging habitats of delphinids in southeastern Brazil, we analyzed stable carbon (δ13C) and nitrogen (δ15N) isotopes in muscle samples of the following 10 delphinid species: Sotalia guianensis, Stenella frontalis, Tursiops truncatus, Steno bredanensis, Pseudorca crassidens, Delphinus sp., Lagenodelphis hosei, Stenella attenuata, Stenella longirostris and Grampus griseus. We also compared the δ13C and δ15N values among four populations of S. guianensis. Variation in carbon isotope results from coast to ocean indicated that there was a significant decrease in δ13C values from estuarine dolphins to oceanic species. S. guianensis from Guanabara Bay had the highest mean δ13C value, while oceanic species showed significantly lower δ13C values. The highest δ15N values were observed for P. crassidens and T. truncatus, suggesting that these species occupy the highest trophic position among the delphinids studied here. The oceanic species S. attenuata, G. griseus and L. hosei had the lowest δ15N values. Stable isotope analysis showed that the three populations of S. guianensis in coastal bays had different δ13C values, but similar δ15N results. Guiana dolphins from Sepetiba and Ilha Grande bays had different foraging habitat, with specimens from Ilha Grande showing more negative δ13C values. This study provides further information on the feeding ecology of delphinids occurring in southeastern Brazil, with evidence of distinctive foraging habitats and the occupation of different ecological niches by these species in the study area.
PMCID: PMC3864921  PMID: 24358155
23.  Stereotactic radiosurgery for the treatment of Glomus Jugulare Tumors 
Surgical Neurology International  2013;4(Suppl 6):S429-S435.
The glomus jugulare tumor is a slowly growing benign neoplasm originating from neural crest. There is a high morbidity associated with surgical resection of glomus jugulare. Radiosurgery play a relevant role as a therapeutic option in these tumors and its use has grown in popularity. The authors describe a retrospective series of 15 patients and reviewed the literature about the glomus jugulare tumors.
We reviewed retrospectively the data of 15 patients treated with stereotactic linear accelerator stereotactic radiosurgery (LINAC) radiosurgery between 2006 and 2011.
The average tumor volume was 18.5 cm3. The radiation dose to the tumor margin ranged between 12 and 20 Gy. The neurological status improved in three patients and remained unchanged in 12 patients. One patient developed a transient 7th nerve palsy that improved after clinical treatment. All tumors remained stable in size on follow-up with resonance magnetic images.
The radiosurgery is a safe and effective therapy for patients with glomus jugulare tumor. Despite the short follow-up period and the limited number of patients analyzed, we can infer that radiosurgery produce a tumor growth control with low morbidity, and may be used as a good option to surgical resection in selected cases.
PMCID: PMC3858802  PMID: 24349866
Chemodectoma; glomus jugulare tumor; radiosurgery
25.  The Transcriptomics of Secondary Growth and Wood Formation in Conifers 
In the last years, forestry scientists have adapted genomics and next-generation sequencing (NGS) technologies to the search for candidate genes related to the transcriptomics of secondary growth and wood formation in several tree species. Gymnosperms, in particular, the conifers, are ecologically and economically important, namely, for the production of wood and other forestry end products. Until very recently, no whole genome sequencing of a conifer genome was available. Due to the gradual improvement of the NGS technologies and inherent bioinformatics tools, two draft assemblies of the whole genomes sequence of Picea abies and Picea glauca arose in the current year. These draft genome assemblies will bring new insights about the structure, content, and evolution of the conifer genomes. Furthermore, new directions in the forestry, breeding and research of conifers will be discussed in the following. The identification of genes associated with the xylem transcriptome and the knowledge of their regulatory mechanisms will provide less time-consuming breeding cycles and a high accuracy for the selection of traits related to wood production and quality.
PMCID: PMC3830773  PMID: 24288610

Results 1-25 (39)