Characterization of a Small Auxin-Up RNA (SAUR)-Like Gene Involved in Arabidopsis thaliana Development

The root of Arabidopsis thaliana is used as a model system to unravel the molecular nature of cell elongation and its arrest. From a micro-array performed on roots that were treated with aminocyclopropane-1-carboxylic acid (ACC), the precursor of ethylene, a Small auxin-up RNA (SAUR)-like gene was found to be up regulated. As it appeared as the 76th gene in the family, it was named SAUR76. Root and leaf growth of overexpression lines ectopically expressing SAUR76 indicated the possible involvement of the gene in the division process. Using promoter::GUS and GFP lines strong expression was seen in endodermal and pericycle cells at the end of the elongation zone and during several stages of lateral root primordia development. ACC and IAA/NAA were able to induce a strong up regulation of the gene and changed the expression towards cortical and even epidermal cells at the beginning of the elongation zone. Confirmation of this up regulation of expression was delivered using qPCR, which also indicated that the expression quickly returned to normal levels when the inducing IAA-stimulus was removed, a behaviour also seen in other SAUR genes. Furthermore, confocal analysis of protein-GFP fusions localized the protein in the nucleus, cytoplasm and plasma membrane. SAUR76 expression was quantified in several mutants in ethylene and auxin-related pathways, which led to the conclusion that the expression of SAUR76 is mainly regulated by the increase in auxin that results from the addition of ACC, rather than by ACC itself.     

Rational design of the survivin/CDK4 complex by combining protein–protein docking and molecular dynamics simulations

Survivin, the smallest inhibitor of apoptosis protein (IAP), is a valid target for cancer research. It mediates both the apoptosis pathway and the cell cycle and has been proposed to form a complex with the cyclin-dependent kinase protein CDK4. The resulting complex transports CDK4 from the cytosol to the nucleus, where CDK4 participates in cell division. Survivin has been recognized as a node protein that interacts with several partners; disruption of the formed complexes can lead to new anticancer compounds. We propose a rational model of the survivin/CDK4 complex that fulfills the experimental evidence and that can be used for structure-based design of inhibitors modifying its interface recognition. In particular, the suggested complex involves the alpha helical domain of survivin and resembles the mode of binding of survivin in the survivin/borealin X-ray structure. The proposed model has been obtained by combining protein–protein docking, fractal-based shape complementarity, electrostatics studies and extensive molecular dynamics simulations.

The timing of sexual maturation among boys and girls in eastern Poland, 1980–2000: A rural–urban comparison

The aim of this study was to determine secular changes in the sexual maturation of children and adolescents from Eastern regions of Poland between 1980 and 2000, with special attention paid to rural–urban differences. Our sample comprised 34,055 girls and 28,100 boys from 9 to 18 years of age. The age at which each gender reached each stage of sexual maturation was examined, along with menarcheal age in girls. An increase in the rate of sexual maturation was observed over the 20-year period of this study. Menarcheal age in girls decreased by 0.59 years. The length of sexual maturation decreased: from 6.58 years to 3.85 years in girls and from 5.84 years to 3.65 years in boys. A significantly faster rate of sexual maturation was observed between 1990 and 2000. Over the entire 20-year period, adolescents living in rural settings experienced a slower rate of sexual maturation than did their urban peers.     

Why pigs are important in Papua? Wealth,height and reproductive success among the Yali tribe of West Papua

Many studies have investigated how different variables influence the reproductive success (RS) in the populations of natural birth control. Here, we tested hypotheses about positive relationship between wealth, height and several measures of RS in an indigenous, traditional society from West Papua. The study was conducted among the Yali tribe in a few small, isolated mountain villages. In this tribe, a man's wealth is measured by the number of pigs he possesses. We found that wealth was related to fertility and number of living children, but not to child mortality in both men and women. Additionally, child mortality increased with the number of children in a family. Finally, we did not observe any relationship between height and reproductive success measures or wealth. We provide several possible explanations of our results and also put forward hypothetical background for further studies of indigenous populations.     

Essential oils from buds and leaves of two hazelnut (Corylus L.) cultivars with different resistance to filbert big bud mite (Phytoptus avellanae Nal.) and filbert aphid (Myzocallis coryli Goetze)

The aim of this study was to identify the allelopatic effect of the components of a mixture of essential oils (EO) contained in the buds and leaves of hazel (Corylus L.) on herbivores. We examined the effect of these compounds on the choice of plants of two different hazel cultivars by Phytoptus avellanae Nal. (filbert big bud mite) and Myzocallis coryli Goetze (filbert aphid), which are the most important pests of hazel in Poland and throughout the world. Our results show that plants of cv. ‘Mogulnus’ were more resistant than those of cv. ‘Barra’ to the feeding of mites and aphids in all study years. Using gas chromatography (GC) and GC/mass spectrometry methodology, we determined the qualitative and quantitative composition of EO in the buds and leaves of plants of these two hazel cultivars. The EO obtained from the analysed materials was a mixture of mono- and sesquiterpenes. The emission of volatile organic compounds from plants is known to repel or attract pests. The mixture of EO present in the hazel buds of cv. ‘Mogulus’, which is resistant to filbert big bud mite, was characterized by a high content of nerol, α-campholenol, methyl salicylate, spatulenol, β-caryophylene and δ-cadinene. In contrast, the leaves of this cultivar, colonized by filbert aphid but to a relatively small extent, contained greater quantities of nerol, α-campholenol, p-cymene, α-terpineol and germacrene D, than the leaves of cv. ‘Barra’, which is more accepted by aphids. However, the leaves of cv. ‘Barra’ were characterized by a considerably high content of menthol, limonene, isomenthone, methyl salicylate and L-menthone.     

Incidence of Spinal Perineurial (Tarlov) Cysts among East-European Patients

The spinal perineurial cyst (Tarlov) is a dilatation between the perineurium and endoneurium of spinal nerve roots, located at level of the spinal ganglion and filled with cerebrospinal fluid but without communication with the perineurial subarachnoid space. The aim of the study was to evaluate it incidence among East-European patients. The retrospective data collected during various magnetic resonance spinal examinations and stored on the picture archiving and communication system was analyzed for an incidence of perineurial cysts. From among 842 patients that underwent examination, 75 cases perineurial cysts were revealed. In 22 cases single anomalies were found. In remaining 53 cases, multiple uni- or less frequently bilateral changes were noted. The most common position was the sacral canal, particularly the level of S2 and S3. Occasionally, cysts were also visible on the cervical, thoracic and lumbar level. Incidence of sacral perineurial cysts was significantly higher in females than in males. Similar data was found for single and multiple changes despite of their localization. Insignificant changes were seen for patient age and cyst size. Perineurial spinal cysts were the most frequently observed on the sacral level and such changes were more common in females.