Development of microsatellite markers for Dimorphandra mollis (Leguminosae), a widespread tree from the Brazilian cerrado

? Premise of the study: Microsatellite markers were developed for Dimorphandra mollis (Leguminosae), a widespread tree in the Brazilian cerrado (a savanna-like vegetation). ? Methods and Results: Microsatellite markers were developed from an enriched library. The analyses of polymorphism were based on 56 individuals from three populations. Nine microsatellite loci were polymorphic, with the number of alleles per locus ranging from three to 10 across populations. The observed and expected heterozygosities per locus and population ranged from 0.062 to 0.850 and from 0.062 to 0.832, respectively. ? Conclusions: These microsatellites provide an efficient tool for population genetics studies and will be used to assess the genetic diversity and spatial genetic structure of D. mollis.     

A new species of Cinclodes from the Espinhaço Range,southeastern Brazil: insights into the biogeographical history of the South American highlands

We describe Cinclodes espinhacensis (Furnariidae), a new species discovered at high elevation in the southern portion of the Espinhaço Range, in the state of Minas Gerais, southeastern Brazil. This new taxon is closely related to the Long‐tailed Cinclodes Cinclodes pabsti, endemic to Serra Geral, southern Brazil. We present diagnostic morphological, genetic and vocal characters that support the rank of species for this allopatric taxon. It is readily distinguishable from C. pabsti by its much darker back, chest and flanks, lower body mass, shorter tarsus‐length, lower frequency of vocalizations, and longer duration of calls. DNA sequence data estimate that the divergence time between this new species and Cinclodes pabsti occurred c. 220 000 years ago, during the late Pleistocene. This discovery illustrates remarkable biogeographical connections among the cold regions of South America. The new species has a restricted range and we suggest it meets the criteria of the IUCN Red List category of Endangered.     

Climate change effects on turtles of the genus Kinosternon (Testudines: Kinosternidae): an assessment of habitat suitability and climate niche conservatism

The Chelonian lineage has been exposed to several climate change events along its evolutionary history, but the rapid contemporary change in climate patterns has the potential to erode turtle populations. This study focuses on (1) evaluating the climatically suitable area available for 15 species of mud turtles of the genus Kinosternon, and on (2) assessing whether or not these species retain their ancestral climate niche. Occurrence data was collected for these species and, using the Maxent algorithm and WorldClim bioclimatic variables, suitable present and future climatic niche areas were modeled. In addition, we also carried out climatic niche similarity analyses between pairs of species to evaluate whether these conserve their climatic niche. Our models suggest that most species of Kinosternon will lose a high proportion of their suitable habitat in the future. Most mud turtle species seem to conserve their climatic niche, suggesting the prevalence of niche conservatism in the group. Our results indicate that several mud turtle species could be at severe risk of disappearing over the next few decades due to the loss of climatically suitable areas and of the conservation of their climatic niches.

     

Modeling panic disorder in rodents

Panic disorder (PD) is a subtype of anxiety disorder in which the core phenomenon is the spontaneous occurrence of panic attacks. Although studies with laboratory animals have been instrumental for the understanding of its neurobiology and treatment, few review articles have focused on the validity of the currently used animal models for studying this psychopathology. Therefore, the aim of the present paper is to discuss the strengths and limits of these models in terms of face, construct and predictive validity. Based on the hypothesis that panic attacks are related to defensive responses elicited by proximal threat, most animal models measure the escape responses induced by specific stimuli. Some apply electrical or chemical stimulation to brain regions proposed to modulate fear and panic responses, such as the dorsal periaqueductal grey or the medial hypothalamus. Other models focus on the behavioural consequences caused by the exposure of rodents to ultrasound or natural predators. Finally, the elevated T-maze associates a one-way escape response from an open arm with panic attacks. Despite some limitations, animal models are essential for a better understanding of the neurobiology and pharmacology of PD and for discovering more effective treatments.     

A new subhaplogroup of native American Y-Chromosomes from the Andes

The human Y chromosome contains highly informative markers for making historical inferences about the pre-Columbian peopling of Americas. However, the scarcity of these markers has limited its use in the inference of shared ancestry and past migrations relevant to the origin of the culturally and biologically diverse Native Americans. To identify new single nucleotide polymorphisms (SNPs) and increase the phylogenetic resolution of the major haplogroup Q found in the Americas, we have performed a search for new polymorphisms based on sequencing divergent Y chromosomes identified by microsatellite haplotype analysis. Using this approach, a new Y-SNP (SA01) has been identified in the Andean populations of South America, allowing for the detection of a new sublineage of Q1a3a. This sublineage displays a less complex phylogeographic network of associated microsatellites and more restricted geographic occurrence, and is given the designation Q1a3a4. This result indicates that our approach can be successfully used to identify sublineages of interest in a specific region that allow the investigation of particular histories of human populations.     

Structural organization of the cerebral cortex of the neotropical lizard <Emphasis Type="Italic">Tropidurus hispidus</Emphasis>

Lizards belonging to the Tropiduridae family are “sit-and-wait” foragers, relying mainly on visual identification to catch prey that cross their visual fields. Little is known about the neurobiology of Tropiduridae lizards. We have used neurohistological techniques to study the structural organization of the telencephalon of the neotropical lizard Tropidurus hispidus, paying special attention to the cerebral cortex. As revealed by the Nissl technique and Golgi staining, the telencephalon of T. hispidus follows the squamate pattern, with some differences: the lateral cortex appears relatively atrophic, and most of the neuronal somata of the dorsal cortex are dispersed without forming a conspicuous cell layer. Golgi staining has revealed ten different neuronal types in the three cortical layers, based on somata shape and dendritic morphology: the granular (unipolar, bipolar, and multipolar), pyramidal (normal, inverted, open, bipyramidal, and horizontal), spherical horizontal, and fusiform neuronal types. The axon direction could be traced in five of the subtypes. We have also studied the distribution of zinc-enriched terminals in the telencephalon of T. hispidus by the Neo-Timm method. Some portions of the cortex, septum, striatum, and amygdaloid complex stain heavily, with patterns resembling those described for other lizard families. Thus, T. hispidus appears to be an interesting representative of the Tropiduridae family for further neurobiological comparative studies.     

Resveratrol prevents oxidative stress and inhibition of Na(+)K(+)-ATPase activity induced by transient global cerebral ischemia in rats

Increased oxidative stress and energy metabolism deficit have been regarded as an important underlying cause for neuronal damage induced by cerebral ischemia/reperfusion (I/R) injury. In this study, we investigated the oxidative mechanisms underlying the neuroprotective effects of resveratrol, a potent polyphenol antioxidant found in grapes, on structural and biochemical abnormalities in rats subjected to global cerebral ischemia. Experimental model of transient global cerebral ischemia was induced in Wistar rats by the four vessel occlusion method for 10 min and followed by different periods of reperfusion. Nissl and fluoro jade C stained indicated extensive neuronal death at 7 days after I/R. These findings were preceded by a rapid increase in the generation of reactive oxygen species (ROS), nitric oxide (NO), lipid peroxidation, as well as by a decrease in Na⁺K⁺-ATPase activity and disrupted antioxidant defenses (enzymatic and non-enzymatic) in hippocampus and cortex. Administrating resveratrol 7 days prior to ischemia by intraperitoneal injections (30 mg/kg) significantly attenuated neuronal death in both studied structures, as well as decreased the generation of ROS, lipid peroxidation and NO content. Furthermore, resveratrol brought antioxidant and Na⁺K⁺-ATPase activity in cortex and hippocampus back to normal levels. These results support that resveratrol could be used as a preventive, or therapeutic, agent in global cerebral ischemia and suggest that scavenging of ROS contributes, at least in part, to resveratrol-induced neuroprotection.     

Modulation of ERG Genes Expression in Clinical Isolates of Candida tropicalis Susceptible and Resistant to Fluconazole and Itraconazole

Mycopathologia - Candida tropicalis is a non-albicans Candida specie that causes candidosis in several countries, including Brazil. However, little is known about the mechanisms of drug resistance...     

Osteopontin-c splicing isoform contributes to ovarian cancer progression

Ovarian carcinoma is one of the most aggressive gynecological diseases and generally diagnosed at advanced stages. Osteopontin (OPN) is one of the proteins overexpressed in ovarian cancer and is involved in tumorigenesis and metastasis. Alternative splicing of OPN leads to 3 isoforms, OPNa, OPNb, and OPNc. However, the expression pattern and the roles of each of these isoforms have not been previously characterized in ovarian cancer. Herein, we have evaluated the expression profiling of OPN isoforms in ovarian tumor and nontumor samples and their putative roles in ovarian cancer biology using in vitro and in vivo functional assays. OPNa and OPNb were expressed both in tumor and nontumor ovarian samples, whereas OPNc was specifically expressed in ovarian tumor samples. The isoform OPNc significantly activated OvCar-3 cell proliferation, migration, invasion, anchorage-independent growth and tumor formation in vivo. Additionally, we have also shown that some of the OPNc-dependent protumorigenic roles are mediated by PI3K/Akt signaling pathway. OPNc stimulated immortalized ovarian epithelial IOSE cell proliferation, indicating a role for this isoform in ovarian cancer tumorigenesis. Functional assays using OPNc conditioned medium and an anti-OPNc antibody have shown that most cellular effects observed herein were promoted by the secreted OPNc. According to our data, OPNc-specific expression in ovarian tumor samples and its role on favoring different aspects of ovarian cancer progression suggest that secreted OPNc contributes to the physiopathology of ovarian cancer progression and tumorigenesis. Altogether, the data open possibilities of new therapeutic approaches for ovarian cancer that selectively down regulate OPNc, altering its properties favoring ovarian tumor progression.