Knowledge and use of medicinal plants by local specialists in an region of Atlantic Forest in the state of Pernambuco (Northeastern Brazil)

This paper investigates the wealth of medicinal plants used by the Apatani tribe of Arunachal Pradesh. Apatani have traditionally settled in seven villages in the Ziro valley of Lower Subansiri district of Arunachal Pradesh in the Eastern Himalayan region of India. The present study has resulted in the documentation of 158 medicinal plant species used by the Apatani group of villages. These medicinal plant species were distributed across 73 families and 124 genera. Asteraceae was the most dominant family (19 species, 11 genera) of medicinal plants, followed by Zingiberaceae, Solanaceae, Lamiaceae and Araceae. For curing ailments, the use of aboveground plant parts was higher (80%) than the belowground plant parts in the Apatani group of villages. Of the aboveground plant parts, leaf was used in the majority of cases (56 species), followed by fruit. Different belowground plant forms such as root, tuber, rhizome, bulb and pseudo-bulb were used by Apatani as a medicine. About 52 types of ailments were cured by using these 158 medicinal plant species. The results of this study are further discussed in the changing socio-economic contexts.     

New terpenoids from Maytenus apurimacensis as MDR reversal agents in the parasite Leishmania

Two new sesquiterpenes (1-2) and one new lupane triterpene (3) have been isolated from the roots of Maytenus apurimacensis. The novel beta-dihydroagarofurans are the first sesquiterpenes with a basic polyhydroxy skeleton of 15-deoxyalatol and 4,15-dideoxyalatol that show high MDR reversing activity in the protozoan parasite Leishmania tropica.     

Effects of structural heterogeneity provided by the floating macrophyte <Emphasis Type="Italic">Eichhornia azurea</Emphasis> on the predation efficiency and habitat use of the small Neotropical fish <Emphasis Type="Italic">Moenkhausia sanctaefilomenae</Emphasis>

Macrophytes have a fundamental structuring role in aquatic environments. Several authors have suggested that trophic interactions are particularly mediated by aquatic plants. In the current article, we evaluated the effects of the structural heterogeneity provided by Eichhornia azurea (Kunth) roots on predation and habitat use by the small fish Moenkhausia sanctaefilomenae (Steindachner). We tested the hypotheses that (i) high structural heterogeneity protects macroinvertebrates against predation by M. sanctaefilomenae; (ii) distinct prey types are differently protected by the refuge provided by roots; and (iii) the behavior of M. sanctaefilomenae is affected by the structural heterogeneity provided by macrophyte roots. To test these hypotheses, we performed an experiment in 20 l aquaria in which macroinvertebrates (Cypricercus sp. and Chironomus sp.) were exposed to M. sanctaefilomenae predation for 4 h under three structural heterogeneities, represented by different root densities. High structural heterogeneity protected macroinvertebrates against predation. Additionally, E. azurea roots similarly protected different prey species. The macrophyte spatial structure substantially changed the habitat use of M. sanctaefilomenae. In general, our results corroborated the hypothesis that the structural heterogeneity provided by E. azurea roots significantly affects predation and habitat use by M. sanctaefilomenae. Handling editor: S. Declerck     

Morphological variation in a secondary contact between divergent lineages of brown trout (Salmo trutta) from the Iberian Peninsula

The aim of this study was to analyze the morphological variation of brown trout (Salmo trutta) in the Duero basin, an Atlantic river basin in the Iberian Peninsula, where a spatial segregation of two divergent lineages was previously reported, based on isozyme, microsatellite and mtDNA data. In these studies, two divergent pure regions (Pisuerga and Lower-course) and several hybrid populations between them were identified. Morphological variation was evaluated in 11 populations representative of the genetic differentiation previously observed in the Duero basin, using multivariate analysis on 12 morphometric and 4 meristic traits. A large differentiation between populations was observed (interpopulation component of variance: 41.8%), similar to that previously detected with allozymes and microsatellites. Morphometric differentiation was also reflected by the high classification success of pure and hybrid individuals to their respective populations, using multivariate discriminant functions (94.1% and 79.0%, respectively). All multivariate and clustering analyses performed demonstrated a strong differentiation between the pure regions. The hybrid populations, though showing large differentiation among them, evidenced an intermediate position between the pure samples. Head and body shape traits were the most discriminant among the morphometric characters, while pectoral rays and gillrakers were the most discriminant among the meristic traits. These results confirmed the high divergence of the brown trout from the Duero basin and suggest some traits on which selection could be acting to explain the spatial segregation observed.     

Amplified label-free electrocatalytic detection of DNA in the presence of calcium ions

A new label-free electrocatalytic method for the detection of DNA, is presented, in which DNA is the catalyst. The method takes advantage of the catalytic properties of the electrooxidised adenines within DNA toward the oxidation of NADH. This catalytic event results in an enhancement in the oxidation current of the electrooxidised adenines within DNA. Further improvement in this analytical signal is achieved in the presence of Ca(2+) ions. Parameters affecting the electrocatalytic current, such as pH or concentration of Ca(2+) ions have been investigated and optimised. Finally, the analytical features of the developed method are obtained. This method constitutes a more sensitive and reproducible alternative to other methods that use the oxidation current of the electrooxidised adenines without coupling to any catalytic event. A limit of detection of 33 fmol deoxyadenylic acid icosanucleotide (dA)(20), is obtained without labels.     

Microsatellite marker development in the protozoan parasite Perkinsus olseni

The analysis of an enriched partial genomic library and of public expressed sequence tag (EST) resources allowed the characterization of the first microsatellite loci in the protozoan parasite Perkinsus olseni. Clonal cultures from laboratory isolates derived from infected clams Ruditapes decussatus (from Spain), R. philippinarum (from Spain and Japan), and Austrovenus stutchburyi (from New Zealand) were used for the characterization of 12 microsatellites. Low variation was detected at most loci, with the number of alleles at polymorphic loci ranging from 2 to 7 (average 3.20 +/- 0.51) and gene diversity from 0.11 to 0.79 (average 0.40 +/- 0.07). Preliminary results show that (1) isolates of P. olseni are diploid cells, and (2) multiple infections can occur within a single host. Eight of the loci analyzed successfully cross-amplified in the congeneric species P. mediterraneus. These microsatellite markers will be useful to analyze in detail the population genetic structure of P. olseni, crucial for the efficient management of this parasitic disease.     

Nanomechanics of the cadherin ectodomain: "canalization" by Ca2+ binding results in a new mechanical element

Cadherins form a large family of calcium-dependent cell-cell adhesion receptors involved in development, morphogenesis, synaptogenesis, differentiation, and carcinogenesis through signal mechanotransduction using an adaptor complex that connects them to the cytoskeleton. However, the molecular mechanisms underlying mechanotransduction through cadherins remain unknown, although their extracellular region (ectodomain) is thought to be critical in this process. By single molecule force spectroscopy, molecular dynamics simulations, and protein engineering, here we have directly examined the nanomechanics of the C-cadherin ectodomain and found it to be strongly dependent on the calcium concentration. In the presence of calcium, the ectodomain extends through a defined ("canalized") pathway that involves two mechanical resistance elements: a mechanical clamp from the cadherin domains and a novel mechanostable component from the interdomain calcium-binding regions ("calcium rivet") that is abolished by magnesium replacement and in a mutant intended to impede calcium coordination. By contrast, in the absence of calcium, the mechanical response of the ectodomain becomes largely "decanalized" and destabilized. The cadherin ectodomain may therefore behave as a calcium-switched "mechanical antenna" with very different mechanical responses depending on calcium concentration (which would affect its mechanical integrity and force transmission capability). The versatile mechanical design of the cadherin ectodomain and its dependence on extracellular calcium facilitate a variety of mechanical responses that, we hypothesize, could influence the various adhesive properties mediated by cadherins in tissue morphogenesis, synaptic plasticity, and disease. Our work represents the first step toward the mechanical characterization of the cadherin system, opening the door to understanding the mechanical bases of its mechanotransduction.     

A sex-associated sequence identified by RAPD screening in gynogenetic individuals of turbot (Scophthalmus maximus)

Understanding the genetic basis of sex determination mechanisms is essential for improving the productivity of farmed aquaculture fish species like turbot (Scophthalmus maximus). In culture conditions turbot males grow slower than females starting from eight months post-hatch, and this differential growth rate is maintained until sexual maturation is reached, being mature females almost twice as big as males of the same age. The goal of this study was to identify sex-specific DNA markers in turbot using comparative random amplified polymorphism DNA (RAPD) profiles in males and females to get new insights of the genetic architecture related to sex determination. In order to do this, we analyzed 540 commercial 10-mer RAPD primers in male and female pools of a gynogenetic family because of its higher inbreeding, which facilitates the detection of associations across the genome. Two sex-linked RAPD markers were identified in the female pool and one in the male pool. After the analysis of the three markers on individual samples of each pool and also in unrelated individuals, only one RAPD showed significant association with females. This marker was isolated, cloned and sequenced, containing two sequences, a microsatellite (SEX01) and a minisatellite (SEX02), which were mapped in the turbot reference map. From this map position, through a comparative mapping approach, we identified Foxl2, a relevant gene related to initial steps of sex differentiation, and Wnt4, a gene related with ovarian development, close to the microsatellite and minisatellite markers, respectively. The position of Foxl2 and Wnt4 was confirmed by linkage mapping in the reference turbot map.