Cyclosporin-A Inhibits Constitutive Nitric Oxide Synthase Activity and Neuronal and Endothelial Nitric Oxide Synthase Expressions after Spinal Cord Injury in Rats

Nitric oxide (NO) plays a role in the pathophysiology of spinal cord injury (SCI). NO is produced by three types of nitric oxide synthase (NOS) enzymes: The constitutive Ca²⁺/calmodulin-dependent neuronal NOS (nNOS) and endothelial NOS (eNOS) isoforms, and the inducible calcium-independent isoform (iNOS). During the early stages of SCI, nNOS and eNOS produce significant amounts of NO, therefore, the regulation of their activity and expression may participate in the damage after SCI. In the present study, we used Cyclosporin-A (CsA) to further substantiate the role of Ca-dependent NOS in neural responses associated to SCI. Female Wistar rats were subjected to SCI by contusion, and killed 4 h after lesion. Results showed an increase in the activity of constitutive NOS (cNOS) after lesion, inhibited by CsA (2.5 mg/kg i.p.). Western blot assays showed an increased expression of both nNOS and eNOS after trauma, also antagonized by CsA administration.     

Fire, rain and the selection of seeder and resprouter life-histories in fire-recruiting, woody plants

Several Cape species of the genus Erica are known to present seeder and resprouter phenotypes, and this variation seems to have a genetic basis. Therefore, this genus provides ideal model systems for using to elucidate the evolution of nonsprouting or seeder and resprouter life-histories in woody, fire-recruiting plants. A simple simulation model was developed to identify, under life-history optimality, the ecological conditions (viz. rainfall conditions and fire frequency) that conferred a selective advantage to the seeder phenotype over the resprouter in a given Cape Erica species. The model illustrated that the seeder life-history was able to invade and replace a resprouter population only under a mild mediterranean climate, with short, moderate summer droughts. This simulation approach will contribute to a better understanding of the biogeographical pattern of seeder and resprouter lineages of one of the paradigmatic fynbos woody taxa throughout the Cape floristic region.     

FIGENIX: Intelligent automation of genomic annotation: expertise integration in a new software platform

Background  

Two of the main objectives of the genomic and post-genomic era are to structurally and functionally annotate genomes which consists of detecting genes' position and structure, and inferring their function (as well as of other features of genomes). Structural and functional annotation both require the complex chaining of numerous different software, algorithms and methods under the supervision of a biologist. The automation of these pipelines is necessary to manage huge amounts of data released by sequencing projects. Several pipelines already automate some of these complex chaining but still necessitate an important contribution of biologists for supervising and controlling the results at various steps.     

Biofiltering efficiency in removal of dissolved nutrients by three species of estuarine macroalgae cultivated with sea bass (Dicentrarchus labrax) waste waters 1. Phosphate

The potential of three estuarine macroalgae (Ulvarotundata, Enteromorpa intestinalis andGracilaria gracilis) as biofilters for phosphate ineffluents of a sea bass (Dicentrarchus labrax) cultivationtank was studied. These seaweeds thrive in Cádiz Bay and were alsoselected because of their economic potential, so that environmental andeconomicadvantages may be achieved by future integrated aquaculture practices in thelocal fish farms. The study was designed to investigate the functioning of Pnutrition of the selected species. Maximum velocity of phosphate uptake (2.86mol PO₄ g^–1 dry wth^–1) was found in U. rotundata.This species also showed the highest affinity for this nutrient. At low flowrates (< 2 volumes d^–1), the three species efficientlyfiltered the phosphate dissolved in the waste water, with a minimum efficiencyof 60.7% in U. rotundata. Net phosphate uptake rate wassignificantly affected by the water flow, being greatest at the highest rateassayed (2 volumes d^–1). The marked decrease in tissue P shownby the three species during a flow-through experiment suggested that growth wasP limited. However, due to the increase in biomass, total P biomass increasedinthe cultures. A significant correlation was found between growth rates and thenet P biomass gained in the cultures. A three-stage design under low water flow(0.5 volumes d^–1) showed that the highest growth rates (up to0.14 d^–1) and integrated phosphate uptake rates(up to 5.8 mol PO₄ ^3– g^–1dry wt d^–1) were found in E.intestinalis in the first stage, with decreasing rates in thefollowing ones. As a result, phosphate become limiting and low increments oreven losses of total P biomass in these stages were found suggesting thatphosphate was excreted from the algae. The results show the potential abilityofthe three species to reduce substantially, at low water flow, the phosphateconcentration in waste waters from a D. labrax cultivationtank, and thus the quality of effluents from intensive aquaculture practices.     

Characterization of sex chromosomes in rainbow trout and coho salmon using fluorescence in situ hybridization (FISH)

With the aim of characterizing the sex chromosomes of rainbow trout (Oncorhynchus mykiss) and to identify the sex chromosomes of coho salmon (O. kisutch), we used molecular markers OmyP9, 5S rDNA, and a growth hormone gene fragment (GH2), as FISH probes. Metaphase chromosomes were obtained from lymphocyte cultures from farm specimens of rainbow trout and coho salmon. Rainbow trout sex marker OmyP9 hybridizes on the sex chromosomes of rainbow trout, while in coho salmon, fluorescent signals were localized in the medial region of the long arm of one subtelocentric chromosome pair. This hybridization pattern together with the hybridization of a GH2 intron probe on a chromosome pair having the same morphology, suggests that a subtelocentric pair could be the sex chromosomes in this species. We confirm that in rainbow trout, one of the two loci for 5S rDNA genes is on the X chromosome. In males of this species that lack a heteromorphic sex pair (XX males), the 5S rDNA probe hybridized to both subtelocentrics This finding is discussed in relation to the hypothesis of intraspecific polymorphism of sex chromosomes in rainbow trout.     

Iron-induced oxidative stress up-regulates calreticulin levels in intestinal epithelial (Caco-2) cells

Calreticulin, a molecular chaperone involved in the folding of endoplasmic reticulum synthesized proteins, is also a shock protein induced by heat, food deprivation, and chemical stress. Mobilferrin, a cytosolic isoform of calreticulin, has been proposed to be an iron carrier for iron recently incoming into intestinal cells. To test the hypothesis that iron could affect calreticulin expression, we investigated the possible associations of calreticulin with iron metabolism. To that end, using Caco-2 cells as a model of intestinal epithelium, the mass and mRNA levels of calreticulin were evaluated as a function of the iron concentration in the culture media. Increasing the iron content in the culture from 1 to 20 microM produced an increase in calreticulin mRNA and a two-fold increase in calreticulin. Increasing iron also induced oxidative damage to proteins, as assessed by the formation of 4-hydroxy-2-nonenal adducts. Co-culture of cells with the antioxidants quercetin, dimethyltiourea and N-acetyl cysteine abolished both the iron-induced oxidative damage and the iron-induced increase in calreticulin. We postulate that the iron-induced expression of calreticulin is part of the cellular response to oxidative stress generated by iron.     

Nest‐site selection by Slender‐billed Parakeets in a Chilean agricultural‐forest mosaic

ABSTRACT Species in the family Psittacidae may be particularly vulnerable to anthropogenic habitat transformations that reduce availability of suitable breeding sites at different spatial scales. In southern Chile, loss of native forest cover due to agricultural conversion may impact populations of Slender‐billed Parakeets (Enicognathus leptorhynchus), endemic secondary cavity‐nesting psittacids. Our objective was to assess nest‐site selection by Slender‐billed Parakeets in an agricultural‐forest mosaic of southern Chile at two spatial scales: nest trees and the habitat surrounding those trees. During the 2008–2009 breeding seasons, we identified nest sites (N= 31) by observing parakeet behavior and using information provided by local residents. Most (29/31) nests were in mature Nothofagus obliqua trees. By comparing trees used for nesting with randomly selected, unused trees, we found that the probability of a tree being selected as a nest site was positively related to the number of cavity entrances, less dead crown, and more basal injuries (e.g., fire scars). At the nesting‐habitat scale, nest site selection was positively associated with the extent of basal injuries and number of cavity entrances in trees within 50 m of nest trees. These variables are likely important because they allow nesting parakeets to minimize cavity search times in potential nesting areas, thereby reducing energetic demands and potential exposure to predators. Slender‐billed Parakeets may thus use a hierarchical process to select nest sites; after a habitat patch is chosen, parakeets may then inspect individual trees in search of a suitable nest site. Effective strategies to ensure persistence of Slender‐billed Parakeets in agricultural‐forest mosaics should include preservation of both individual and groups of scattered mature trees.     

Effect of chronic ethanol consumption on postnatal development of renal (Na + K)-ATPase in the rat.

Renal (Na + K)-ATPase was studied to ascertain whether it follows the pattern of adaptation of membrane-bound enzymes that are inhibited by acute ethanol exposure and develop greater activity after chronic ethanol treatment. A colony of rats was given 20 per cent (v/v) ethanol as sole drinking solution throughout gestation, lactation and following weaning. (Na + K)-ATPase and ouabain-insensitive Ca(2+)-ATPase activities were determined; regional distribution of these enzymes was assessed in renal cortex and outer medulla. Control rats drank tap water. (Na + K)-ATPase in whole homogenate of kidney increased with age in controls and ethanol-fed rats, but the latter showed higher values at every age studied. Between 15 and 60 days of age, the control group showed 2-fold increases in cortex and 5-fold in outer medulla, whereas ethanol-fed rats reached a 3-fold increase in the enzyme activity in both renal regions. Ca(2+)-ATPase showed the same time course in developing kidney of both groups. Chronic ethanol treatment of adult rats resulted in an increase of (Na + K)-ATPase activity in cortex and outer medulla, but no change in other ATPases. Since an earlier maturational development of renal (Na + K)-ATPase was displayed by ethanol-fed rats, underlying mechanisms that may account for these results are discussed.     

Impact of chromatin context on Cas9-induced DNA double-strand break repair pathway balance

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