Genomic evidence for homoploid hybrid speciation in a marine mammal apex predator.

Hybridization is widespread and constitutes an important source of genetic variability and evolution. In animals, its role in generating novel and independent lineages (hybrid speciation) has been strongly debated, with only a few cases supported by genomic data. The South American fur seal (SAfs) Arctocephalus australis is a marine apex predator of Pacific and Atlantic waters, with a disjunct set of populations in Peru and Northern Chile [Peruvian fur seal (Pfs)] with controversial taxonomic status. We demonstrate, using complete genome and reduced representation sequencing, that the Pfs is a genetically distinct species with an admixed genome that originated from hybridization between the SAfs and the Galapagos fur seal (Arctocephalus galapagoensis) ~400,000 years ago. Our results strongly support the origin of Pfs by homoploid hybrid speciation over alternative introgression scenarios. This study highlights the role of hybridization in promoting species-level biodiversity in large vertebrates.

Comparative Evaluation of Radiochemical and Biological Properties of 131I- and [99mTc]Tc(CO)3-Labeled RGD Analogues Planned to Interact with the αvß3 Integrin Expressed in Glioblastoma.

Radiolabeled peptides with high specificity for overexpressed receptors in tumor cells hold great promise for diagnostic and therapeutic applications. In this work, we aimed at comparing the radiolabeling efficiency and biological properties of two different RGD analogs: GRGDYV and GRGDHV, labeled with iodine-131 (131I) and technetium-99m-tricarbonyl complex [99mTc][Tc(CO)3]+. Additionally, we evaluated their interaction with the αvß3 integrin molecule, overexpressed in a wide variety of tumors, including glioblastoma. Both peptides were chemically synthesized, purified and radiolabeled with 131I and [99mTc][Tc(CO)3]+ using the chloramine-T and tricarbonyl methodologies, respectively. The stability, binding to serum proteins and partition coefficient were evaluated for both radioconjugates. In addition, the binding and internalization of radiopeptides to rat C6 glioblastoma cells and rat brain homogenates from normal animals and a glioblastoma-induced model were assessed. Finally, ex vivo biodistribution studies were carried out. Radiochemical yields between 95-98% were reached for both peptides under optimized radiolabeling conditions. Both peptides were stable for up to 24 h in saline solution and in human serum. In addition, the radiopeptides have hydrophilic characteristics and a percentage of binding to serum proteins around 35% and 50% for the [131I]I-GRGDYV and [99mTc]Tc(CO)3-GRGDHV fragments, respectively. Radiopeptides showed the capacity of binding and internalization both in cell culture (C6) and rat brain homogenates. Biodistribution studies corroborated the results obtained with brain homogenates and confirmed the different binding characteristics due to the exchange of radionuclides and the presence of the tricarbonyl complex. Thereby, the results showed that both radiopeptides might be considered for future clinical applications.

Phylogenomic Discordance in the Eared Seals is best explained by Incomplete Lineage Sorting following Explosive Radiation in the Southern Hemisphere.

The phylogeny and systematics of fur seals and sea lions (Otariidae) have long been studied with diverse data types, including an increasing amount of molecular data. However, only a few phylogenetic relationships have reached acceptance because of strong gene-tree species tree discordance. Divergence times estimates in the group also vary largely between studies. These uncertainties impeded the understanding of the biogeographical history of the group, such as when and how trans-equatorial dispersal and subsequent speciation events occurred. Here, we used high-coverage genome-wide sequencing for 14 of the 15 species of Otariidae to elucidate the phylogeny of the family and its bearing on the taxonomy and biogeographical history. Despite extreme topological discordance among gene trees, we found a fully supported species tree that agrees with the few well-accepted relationships and establishes monophyly of the genus Arctocephalus. Our data support a relatively recent trans-hemispheric dispersal at the base of a southern clade, which rapidly diversified into six major lineages between 3 and 2.5 Ma. Otaria diverged first, followed by Phocarctos and then four major lineages within Arctocephalus. However, we found Zalophus to be nonmonophyletic, with California (Zalophus californianus) and Steller sea lions (Eumetopias jubatus) grouping closer than the Galapagos sea lion (Zalophus wollebaeki) with evidence for introgression between the two genera. Overall, the high degree of genealogical discordance was best explained by incomplete lineage sorting resulting from quasi-simultaneous speciation within the southern clade with introgresssion playing a subordinate role in explaining the incongruence among and within prior phylogenetic studies of the family. [Hybridization; ILS; phylogenomics; Pleistocene; Pliocene; monophyly.].

Radiochemical and biological properties of peptides designed to interact with EGF receptor: Relevance for glioblastoma.

Radiolabeled peptides with high specificity to receptors expressed on tumor cells hold a great promise as diagnostic and therapeutic tracers. The main objective of this study was to evaluate the radiochemical and biological properties of two [131I]I-peptides, as well as their interaction with the epidermal growth factor receptor (EGFR), overexpressed in a wide variety of tumors, including glioblastoma. The EEEEYFELV peptide and its analogue DEDEYFELV, both designed to interact with EGFR, were chemically synthesized, purified and radiolabeled with iodine-131 ([131I]NaI). The radioiodination was evaluated and optimized using the chloramine-T methodology. The stability, serum proteins binding and partition coefficient were assessed for both radioconjugates. Moreover, the binding and internalization of synthesized radiopeptides with rat glioblastoma cells (C6) and with rat brain homogenates from a glioblastoma induced model were evaluated and ex vivo biodistribution studies were performed. Under optimized radiolabeling conditions, the peptides showed an average radiochemical yield of 90-95%. The stability studies showed that both peptides were stable up to 24 h in reaction medium, saline, and human serum. Furthermore, [131I]I-peptides have hydrophilic features and showed binding percentage to serum proteins of around 50%, which is highly compatible with clinical applications. Moreover, the radiopeptides presented capacity for binding and internalization in both tumor cells (C6) and rat brain tissues after tumor induction. Biodistribution studies corroborated the cell culture studies and confirmed the different binding characteristics derived from a simple change of two amino acids (Glu ➔ Asp1,3) in their sequences. The results obtained are consistent enough to motivate further studies. Thereby, these radiolabeled peptides might be useful for diagnostic applications.

Uncovering population structure in the Humboldt penguin (Spheniscus humboldti) along the Pacific coast at South America.

The upwelling hypothesis has been proposed to explain reduced or lack of population structure in seabird species specialized in food resources available at cold-water upwellings. However, population genetic structure may be challenging to detect in species with large population sizes, since variation in allele frequencies are more robust under genetic drift. High gene flow among populations, that can be constant or pulses of migration in a short period, may also decrease power of algorithms to detect genetic structure. Penguin species usually have large population sizes, high migratory ability but philopatric behavior, and recent investigations debate the existence of subtle population structure for some species not detected before. Previous study on Humboldt penguins found lack of population genetic structure for colonies of Punta San Juan and from South Chile. Here, we used mtDNA and nuclear markers (10 microsatellites and RAG1 intron) to evaluate population structure for 11 main breeding colonies of Humboldt penguins, covering the whole spatial distribution of this species. Although mtDNA failed to detect population structure, microsatellite loci and nuclear intron detected population structure along its latitudinal distribution. Microsatellite showed significant Rst values between most of pairwise locations (44 of 56 locations, Rst = 0.003 to 0.081) and 86% of individuals were assigned to their sampled colony, suggesting philopatry. STRUCTURE detected three main genetic clusters according to geographical locations: i) Peru; ii) North of Chile; and iii) Central-South of Chile. The Humboldt penguin shows signal population expansion after the Last Glacial Maximum (LGM), suggesting that the genetic structure of the species is a result of population dynamics and foraging colder water upwelling that favor gene flow and phylopatric rate. Our findings thus highlight that variable markers and wide sampling along the species distribution are crucial to better understand genetic population structure in animals with high dispersal ability.

Correlations between brain changes and pain management after cognitive and meditative therapies: A systematic review of neuroimaging studies.

BACKGROUND: There are different ways of dealing with pain and cognitive and meditative therapies (CMT) are alternative ways to regulate the emotions associated with pain. Current studies apply neuroimaging techniques trying to elucidate the neural mechanisms of cognitive strategies for pain. This systematic review aimed to summarize the evidence on brain activity changes after CMT, which include cognitive behavioral therapy, mindfulness and/or meditation, for pain management as well as to evaluate clinical pain outcomes. METHODS: Electronic databases - Pubmed, EMBASE, PsycINFO, Science Direct, Scopus - were searched to find randomized controlled trials (RCTs) examining neuroimaging data of CMT for chronic pain patients or healthy individuals with experimental pain. Two reviewers independently selected the relevant trials, rated for quality assessment and extracted all data using a standardized form. Primary outcome was brain activity changes (activation, deactivation or functional connectivity). Secondary outcomes were pain intensity, self-management, pain coping, quality of life, anxiety and depression. RESULTS: Nine RCTs were included involving 280 adults (18-59 years), 139 chronic pain patients vs. 148 healthy subjects. Three main kinds of intervention were identified: cognitive-behavioral therapy (n = 4), mindfulness meditation (n = 4) and transcendental meditation technique (n = 1). Neuroimaging results revealed distinct patterns of activity, but the main findings were related to increased activation of prefrontal cortex (PFC), specially dorsolateral prefrontal cortex (dlPFC) and ventrolateral prefrontal cortex (vlPFC), orbitofrontal cortex (OBF), somatosensory cortices (SSC) and limbic system in chronic pain population; and increased activation of anterior cingulate cortex (ACC), anterior insular cortex (AI) and decreased activation of thalamus in healthy individuals following CMT. CONCLUSION: This result means that regulation of pain by CMT can alter functioning of brain regions in an extensive network including non-nociceptive regions. CMT reduced the affective experience of pain, while reductions of pain intensity ratings were less consistent. Brain changes have been demonstrated as a result of the application of psychological measures and may represent the clinical implications of changes in brain activity or morphology.

Molecular Identification of Shark Meat From Local Markets in Southern Brazil Based on DNA Barcoding: Evidence for Mislabeling and Trade of Endangered Species.

Elasmobranchs, the group of cartilaginous fishes that include sharks and rays, are especially vulnerable to overfishing due to low fecundity and late sexual maturation. A significant number of elasmobranch species are currently overexploited or threatened by fisheries activities. Additionally, several recent reports have indicated that there has been a reduction in regional elasmobranch population sizes. Brazil is an important player in elasmobranch fisheries and one of the largest importers of shark meat. However, carcasses entering the shark meat market have usually had their fins and head removed, which poses a challenge to reliable species identification based on the morphology of captured individuals. This is further complicated by the fact that the internal Brazilian market trades several different elasmobranch species under a common popular name: "cação." The use of such imprecise nomenclature, even among governmental agencies, is problematic for both controlling the negative effects of shark consumption and informing the consumer about the origins of the product. In this study, we used DNA barcoding (mtDNA, COI gene) to identify, at the species level, "cação" samples available in local markets from Southern Brazil. We collected 63 samples traded as "cação," which we found to correspond to 20 different species. These included two teleost species: Xiphias gladius (n = 1) and Genidens barbus (n = 6), and 18 species from seven elasmobranch orders (Carcharhiniformes, n = 42; Squaliformes, n = 3; Squatiniformes, n = 2; Rhinopristiformes, n = 4; Myliobatiformes, n = 3; Rajiformes, n = 1; and Torpediniformes, n = 1). The most common species in our sample were Prionace glauca (n = 15) and Sphyrna lewini (n = 14), while all other species were represented by four samples or less. Considering IUCN criteria, 47% of the elasmobranch species found are threatened at the global level, while 53% are threatened and 47% are critically endangered in Brazil. These results underline that labeling the meat of any shark species as "cação" is problematic for monitoring catch allocations from the fishing industry and discourages consumer engagement in conservationist practices through informed decision-making.

Potentiation of antibiotic activity by Passiflora cincinnata Mast. front of strains Staphylococcus aureus and Escherichia coli.

The development of new drugs from plants is an interesting alternative approach to overcoming microbial resistance. Passiflora cincinnata shows resistance to diseases and pests and a higher concentration of chemical components that may be useful in the pharmaceutical industry. We investigated the potential antimicrobial and antibiotic-modifying activity of hydroalcoholic extracts of leaves, stems, bark, pulp and seeds of P. cincinnata. The extracts were prepared by homogenization of material in 50% ethanol. Minimum inhibitory concentration (MIC) was determined by the broth dilution method, and the bacterial strains tested were Staphylococcus aureus and Escherichia coli. Antibiotic-modifying activity was evaluated against the strains S. aureus 03 and E. coli 08, using a subinhibitory concentration of extract. The antibiotics tested were: amikacin, gentamicin, ampicillin, potassium benzylpenicillin and oxacillin. The extracts did not show antimicrobial activity of clinical relevance, where the MIC was equal to or greater than 1024 µg/mL. S. aureus showed 13 events, while E. coli showed only 4 events. Among these events, 14 involved synergistic activity, potentiating the effect of the antibiotics, and only 3 events demonstrated antagonistic activity toward ampicillin. Hydroalcoholic extracts are potential antimicrobial agents when combined with conventional drugs little utilized in in vivo treatment.

Differential Behavior of Non-albicans Candida Species in the Central Nervous System of Immunocompetent and Immunosuppressed Mice.

The genus Candida includes commensal fungi that can cause local and systemic infections, frequently involving vital organs as the central nervous system (CNS). Candida spp. occupy the fourth place among infections that affect the CNS. Although the incidence of Candida albicans is decreasing among patients under immunosuppressive therapies, the incidence of non-albicans Candida is increasing. In this context, the objective of this work was to evaluate the ability of non-albicans Candida species to spread to the CNS of immunocompetent and immunosuppressed mice. Adult female C57BL/6 mice were treated with prednisolone, intravenously infected with Candida glabrata, Candida krusei and Candida parapsilosis yeasts and then evaluated at the 3rd and 14th days after infection. All Candida species disseminated to the brain from immunocompetent animals and induced local inflammation at the third day post-infection. The immunosuppression resulted in body weight loss, leukopenia and reduced IL-2 production by spleen cell cultures. Higher fungal loads were recovered from the CNS of immunosuppressed mice. Inflammatory infiltration associated to a Th1 subset profile was higher in brain samples from C. krusei immunosuppressed mice compared with immunocompetent ones. Additionally, C. krusei was able to transform into pseudohypha inside microglia in vitro infected cells and also to induce elevated nitric oxide production. Altogether, these results indicate that C. glabrata, C. krusei and C. parapsilosis are able to disseminate to the CNS and promote local inflammation in both immunocompetent and immunosuppressed mice. C. krusei displayed a distinct behavior at the CNS triggering a local Th1 profile. The possible contribution of these non-albicans Candida species to other CNS pathologies as multiple sclerosis, Parkinson's and Alzheimer's diseases deserves further attention.

Increased Nitric Oxide Bioavailability and Decreased Sympathetic Modulation Are Involved in Vascular Adjustments Induced by Low-Intensity Resistance Training.

Resistance training is one of the most common kind of exercise used nowadays. Long-term high-intensity resistance training are associated with deleterious effects on vascular adjustments. On the other hand, is unclear whether low-intensity resistance training (LI-RT) is able to induce systemic changes in vascular tone. Thus, we aimed to evaluate the effects of chronic LI-RT on endothelial nitric oxide (NO) bioavailability of mesenteric artery and cardiovascular autonomic modulation in healthy rats. Wistar animals were divided into two groups: exercised (Ex) and sedentary (SED) rats submitted to the resistance (40% of 1RM) or fictitious training for 8 weeks, respectively. After LI-RT, hemodynamic measurements and cardiovascular autonomic modulation by spectral analysis were evaluated. Vascular reactivity, NO production and protein expression of endothelial and neuronal nitric oxide synthase isoforms (eNOS and nNOS, respectively) were evaluated in mesenteric artery. In addition, cardiac superoxide anion production and ventricle morphological changes were also assessed. In vivo measurements revealed a reduction in mean arterial pressure and heart rate after 8 weeks of LI-RT. In vitro studies showed an increased acetylcholine (ACh)-induced vasorelaxation and greater NOS dependence in Ex than SED rats. Hence, decreased phenylephrine-induced vasoconstriction was found in Ex rats. Accordingly, LI-RT increased the NO bioavailability under basal and ACh stimulation conditions, associated with upregulation of eNOS and nNOS protein expression in mesenteric artery. Regarding autonomic control, LI-RT increased spontaneous baroreflex sensitivity, which was associated to reduction in both, cardiac and vascular sympathetic modulation. No changes in cardiac superoxide anion or left ventricle morphometric parameters after LI-RT were observed. In summary, these results suggest that RT promotes beneficial vascular adjustments favoring augmented endothelial NO bioavailability and reduction of sympathetic vascular modulation, without evidence of cardiac overload.

Stranding Events of Kogia Whales along the Brazilian Coast.

The genus Kogia, which comprises only two extant species, Kogia sima and Kogia breviceps, represents one of the least known groups of cetaceans in the global ocean. In some coastal regions, however, stranding events of these species have been relatively common over the last decades. Stranding provides the opportunity to investigate the biology of these cetaceans and to explore the epidemiological aspects associated with the mortality of the organisms found on the beach. A number of disturbances (including pelagic fisheries, chemical pollution, boat strikes, and noise pollution) have been confirmed to pose a particular threat to the Kogia species. However, no study has yet investigated potential relationships between environmental conditions and stranding events. Here we analyse how a collection of environmental, physical, and biological variables, such as wind, sea surface temperature (SST), water depth, and chlorophyll-a, correlate to Kogia stranding events along the Brazilian coast. The results of our statistical analyses suggest that K. sima is more likely found in warm tropical waters, which provide an explanation for the high frequency of stranding in northeastern Brazilian coast. In contrast, K. breviceps appears to have a preference for temperate and productive waters. Wind speed results to be also an important factor for predicting Kogia strandings in Brazilian coast. Additionally, literature information in combination with our own data and analyses of stomach contents confirms that oceanic cephalopods constitute the primary nutritional source of both Kogia species. By using the available information as a qualitative proxy for habitat preference and feeding ecology, our study provides a novel and comprehensive assessment of Kogia stranding data in relation to environmental conditions along the Brazilian coast.

Depredation of domestic herds by pumas based on farmer's information in Southern Brazil.

BACKGROUND: Large carnivores such as pumas are frequently killed due to conflicts with human populations involving predation on domestic herds. In Southern Brazil, traditional pasture systems, where animals feed without specific husbandry practices is typical, becoming the herds vulnerable to puma attacks. The aim of this study was to examine the conflict between local people and pumas in a Protected Areas mosaic in southern Brazil. METHODS: Forty-five face-to-face interviews with local people were performed during the year of 2011, using a structured questionnaire with open and closed questions about puma attack episodes in some farms. Based on responses, the conflict and puma attacks were described, and the characteristics of attacked farms and estimated financial losses were evaluated. The first respondents were indicated by the Local Environmental Agency, and the others were indicated by the first one and so on, which is known as "snow-ball" method. RESULTS: Our data suggested that pumas used to attack in unfavorable conditions of visibility (foggy days) and on easier prey (e.g. sheep). Most of the attacks reported were close to forested areas and were focused on free herds during feeding activities. Some farmers said they gave up their sheep breeding activity due to losses caused by puma attacks. However, some farmers could over estimate their losses. Moreover, pumas were considered a threat to domestic herds and respondents mentioned cases of illegal puma hunting in the area. The results of questionnaires suggested that puma attack episodes were related to fragmentation of their habitat associated to incorrect management of herds in the farms studied. The diagnosis of this type of conflict and the characterization of most attacked sites are extremely important to create strategies to prevent and control attacks by wild carnivores. CONCLUSIONS: Deep changes in husbandry practices added to educational programs should be implemented, in order to maintain the sustainability of rural activities as well as the survival of pumas in southern Brazil.

Stable isotopes indicate population structuring in the southwest Atlantic population of right whales (Eubalaena australis).

From the early 17th century to the 1970s southern right whales, Eubalaena australis, were subject to intense exploitation along the Atlantic coast of South America. Catches along this coast recorded by whalers originally formed a continuum from Brazil to Tierra del Fuego. Nevertheless, the recovery of the population has apparently occurred fragmentarily, and with two main areas of concentration, one off southern Brazil (Santa Catarina) and another off central Argentina (Peninsula Valdés). This pattern suggests some level of heterogeneity amongst the population, which is apparently contradicted by records that traced individuals moving throughout the whole geographical extension covered by the species in the Southwest Atlantic. To test the hypothesis of the potential occurrence of discrete subpopulations exploiting specific habitats, we investigated N, C and O isotopic values in 125 bone samples obtained from whaling factories operating in the early 1970s in southern Brazil (n=72) and from contemporary and more recent strandings occurring in central Argentina (n=53). Results indicated significant differences between the two sampling areas, being δ13C and δ18O values significantly higher in samples from southern Brazil than in those from central Argentina. This variation was consistent with isotopic baselines from the two areas, indicating the occurrence of some level of structure in the Southwest Atlantic right whale population and equally that whales more likely feed in areas commonly thought to exclusively serve as nursing grounds. Results aim at reconsidering of the units currently used in the management of the southern right whale in the Southwest Atlantic Ocean. In the context of the current die-off affecting the species in Peninsula Valdés, these results also highlight the necessity to better understand movements of individuals and precisely identify their feeding areas.

Patterns of arboreal and terrestrial space use by non-volant small mammals in an Araucaria forest of southern Brazil.

Despite the advances in the techniques for researching arboreal small mammals, detailed ecological data, such as habitat use patterns, are practically nonexistent for many species. Using 150 live-traps installed on the ground, understory (1.0-5.0m) and canopy (>5.0m) we investigated patterns of arboreal and terrestrial space use by small mammals in an Araucaria Forest in southern Brazil (29°29'08″S; 50°12'26″W). We also measured 19 microhabitat variables that could potentially influence the abundance of such mammals on each trap station. The results indicated that Akodon montensis and A. serrensis were mainly terrestrial. Delomys dorsalis was also terrestrial, but it also used understory (17.24% of captures). Juliomys sp. and Gracilinanus microtarsus were the most arboreal small mammals recorded. A. montensis was associated with dense vegetation, while A. serrensis selected positively opened areas. Juliomys sp. and G. microtarsus were associated to microhabitat variables related to the access and movement within the canopy. Moreover, bromeliads on arboreal layer were an important factor for these two arboreal species. This is the first study to report microhabitat associations by Juliomys sp. and A. serrensis, and we demonstrated that vertical stratification and microhabitat use were both synergic mechanisms to determine habitat use by small mammals on the Araucaria Forest of southern Brazil.

Antiulcerogenic Activity of the Hydroalcoholic Extract of Leaves of Croton campestris A. St.-Hill in Rodents.

Croton campestris A. St.-Hill., popularly known as "velame do campo," is a species native to the savannah area of Northeast Brazil, which is used by traditional communities in folk medicine for variety of health problems, especially detoxification, inflammation, and gastritis. The hydroalcoholic extract of C. campestris leaves (HELCC) was assessed for its antiulcerogenic effect in gastric lesion models and effect on intestinal motility in mice, and possible mechanisms of action were examined. HELCC showed significant gastroprotective action in all models of gastric ulcer evaluated; the results suggest that this action probably involves the nitric oxide pathway. HELCC did not show alteration of intestinal motility in mice. It was also found that C. campestris represents a promising natural source with important biological potential, justifying some of its uses in folk medicine.

DNA barcoding meets molecular scatology: short mtDNA sequences for standardized species assignment of carnivore noninvasive samples.

Although species assignment of scats is important to study carnivore biology, there is still no standardized assay for the identification of carnivores worldwide, which would allow large-scale routine assessments and reliable cross-comparison of results. Here, we evaluate the potential of two short mtDNA fragments [ATP6 (126 bp) and cytochrome oxidase I gene (COI) (187 bp)] to serve as standard markers for the Carnivora. Samples of 66 species were sequenced for one or both of these segments. Alignments were complemented with archival sequences and analysed with three approaches (tree-based, distance-based and character-based). Intraspecific genetic distances were generally lower than between-species distances, resulting in diagnosable clusters for 86% (ATP6) and 85% (COI) of the species. Notable exceptions were recently diverged species, most of which could still be identified using diagnostic characters and uniqueness of haplotypes or by reducing the geographic scope of the comparison. In silico analyses were also performed for a 110-bp cytochrome b (cytb) segment, whose identification success was lower (70%), possibly due to the smaller number of informative sites and/or the influence of misidentified sequences obtained from GenBank. Finally, we performed case studies with faecal samples, which supported the suitability of our two focal markers for poor-quality DNA and allowed an assessment of prey DNA co-amplification. No evidence of prey DNA contamination was found for ATP6, while some cases were observed for COI and subsequently eliminated by the design of more specific primers. Overall, our results indicate that these segments hold good potential as standard markers for accurate species-level identification in the Carnivora.