Assessment of arbuscular mycorrhizal fungal diversity in roots of Solidago gigantea growing in a polluted soil in Northern Italy

The arbuscular mycorrhizal (AM) status of Solidago gigantea was investigated in a contaminated site of Northern Italy, where the chemical industry ACNA (Associated National Chemical Companies) was active till 1999. To counteract the devastating effects of chemicals and to allow re-vegetation, soil from an uncontaminated area was used to cover the highly polluted hills of the industrial site about 25 years ago. On the basis of the current floristic features, the hill was divided into four areas. Heavy metal content in soil and in plant shoots and roots was determined by chemical analysis. The AM fungal community colonizing S. gigantea was investigated from a morphological and a molecular point of view. All plants were modestly colonized, but the fungal structures within the roots were normal. By PCR-RFLP and sequencing of 18S rDNA, 14 AM fungal types were identified: three of them were present in all the considered areas and nine appeared to be specific to certain areas. Glomus was the predominant AM genus. Our analysis demonstrates the presence and the relatively high level of AM species variety and shows how a remediation programme based on cover-soil has been efficient to restore a community of AM fungi, tolerant enough to proliferate in a still contaminated soil.     

Environmental stress and reproduction in Drosophila melanogaster : starvation resistance, ovariole numbers and early age egg production

Background  

The Y model of resource allocation predicts a tradeoff between reproduction and survival. Environmental stress could affect a tradeoff between reproduction and survival, but the physiological mechanisms underlying environmental mediation of the tradeoff are largely unknown. One example is the tradeoff between starvation resistance and early fecundity. One goal of the present study was to determine if reduced early age fecundity was indeed a robust indirect response to selection for starvation resistance, by investigation of a set of D. melanogaster starvation selected lines which had not previously been characterized for age specific egg production. Another goal of the present study was to investigate a possible relationship between ovariole number and starvation resistance. Ovariole number is correlated with maximum daily fecundity in outbred D. melanogaster. Thus, one might expect that a negative genetic correlation between starvation resistance and early fecundity would be accompanied by a decrease in ovariole number.     

An NMR view of the folding process of a CheY mutant at the residue level

The folding of CheY mutant F14N/V83T was studied at 75 residues by NMR. Fluorescence, NMR, and sedimentation equilibrium studies at different urea and protein concentrations reveal that the urea-induced unfolding of this CheY mutant includes an on-pathway molten globule-like intermediate that can associate off-pathway. The populations of native and denatured forms have been quantified from a series of 15N-1H HSQC spectra recorded under increasing concentrations of urea. A thermodynamic analysis of these data provides a detailed picture of the mutant's unfolding at the residue level: (1) the transition from the native state to the molten globule-like intermediate is highly cooperative, and (2) the unfolding of this state is sequential and yields another intermediate showing a collapsed N-terminal domain and an unfolded C-terminal tail. This state presents a striking similarity to the kinetic transition state of the CheY folding pathway.     

Five-years cumulative incidence of alcohol consumption in Croatian adult population: the CroHort study

Alcohol consumption is traditionally part of most human cultures, and with the onset of industrial revolution it was recognized as a health and social problem. The aim of this article is to investigate cumulative incidence of alcohol consumption in Croatia. Data were obtained from the Croatian Adult health Survey in 2003 followed by 2008. The cohort consisted of 3229 participants. Questions regarding alcohol consumption were calculated into two factors describing existence or non-existence of risk behavior. Results revealed higher incidence of risk alcohol consumption in man than in women and highest in the 35-65, age group. Due to the some study limitations results might be underestimated. Present problem of alcohol is alarming, even more so, in women's population it might be only the tip of the iceberg. Cultural and regional differences should be taken into account when educational programs are constructed, especially due to the different type of alcohol consumed.     

Non-invasive prenatal diagnosis of single-gene disorders from maternal blood

Prenatal diagnosis (PD) is available for pregnancies at risk of monogenic disorders. However, PD requires the use of invasive obstetric techniques for fetal-sample collection and therefore, involves a risk of fetal loss. Circulating fetal DNA in the maternal bloodstream is being used to perform non-invasive prenatal diagnosis (NIPD). NIPD is a challenging discipline because of the biological features of the maternal blood sample. Maternal blood is an unequal mixture of small (and fragmented) amounts of fetal DNA within a wide background of maternal DNA. For this reason, initial NIPD studies have been based on the analysis of specific paternally inherited fetal tracts not present in the maternal genome so as to ensure their fetal origin. Following this strategy, different NIPD studies have been carried out, such as fetal-sex assessment for pregnancies at risk of X-linked disorders, RhD determination, and analysis of single-gene disorders with a paternal origin. The study of the paternal mutation can be used for fetal diagnosis of dominant disorders or to more accurately assess the risk of an affected child in case of recessive diseases. Huntington's disease, cystic fibrosis, or achondroplasia are some examples of diseases studied using NIPD. New technologies are opening NIPD to the analysis of maternally inherited fetal tracts. NIPD of trisomy 21 is the latest study derived from the use of next-generation sequencing (NGS).     

Chiral analysis by online coupling of reversed-phase liquid chromatography to gas chromatography and mass spectrometry

Enantiomeric composition of selected chiral compounds present in complex mixtures is determined by using the online coupling of reversed-phase liquid chromatography (LC) to gas chromatography (GC) and mass spectrometry. Integration of sample preparation into GC analysis, in a completely automated way, is achieved by means of the effective clean-up resulting from both the LC fractionation step and the eluent elimination provided by the through oven transfer adsorption desorption system used for LC-GC interfacing. The possibilities of the technique are illustrated through some examples concerning the stereodifferentiation in essential oils of major and minor chiral compounds via LC-GC transfer of different volume fractions, ranging from 0.5 to 1.9 ml, which show the significance of the window size for the determination of enantiomeric profiles.     

Stay-green in spring wheat can be determined by spectral reflectance measurements (normalized difference vegetation index) independently from phenology

The green area displayed by a crop is a good indicator of its photosynthetic capacity, while chlorophyll retention or 'stay-green' is regarded as a key indicator of stress adaptation. Remote-sensing methods were tested to estimate these parameters in diverse wheat genotypes under different growing conditions. Two wheat populations (a diverse set of 294 advanced lines and a recombinant inbred line population of 169 sister lines derived from the cross between Seri and Babax) were grown in Mexico under three environments: drought, heat, and heat combined with drought. In the two populations studied here, a moderate heritable expression of stay-green was found-when the normalized difference vegetation index (NDVI) at physiological maturity was estimated using the regression of NDVI over time from the mid-stages of grain-filling to physiological maturity-and for the rate of senescence during the same period. Under heat and heat combined with drought environments, stay-green calculated as NDVI at physiological maturity and the rate of senescence, showed positive and negative correlations with yield, respectively. Moreover, stay-green calculated as an estimation of NDVI at physiological maturity and the rate of senescence regressed on degree days give an independent measurement of stay-green without the confounding effect of phenology. On average, in both populations under heat and heat combined with drought environments CTgf and stay-green variables accounted for around 30% of yield variability in multiple regression analysis. It is concluded that stay-green traits may provide cumulative effects, together with other traits, to improve adaptation under stress further.     

Aminoglycoside 2'-phosphotransferase IIIa (APH(2')-IIIa) prefers GTP over ATP: structural templates for nucleotide recognition in the bacterial aminoglycoside-2' kinases

Contrary to the accepted dogma that ATP is the canonical phosphate donor in aminoglycoside kinases and protein kinases, it was recently demonstrated that all members of the bacterial aminoglycoside 2'-phosphotransferase IIIa (APH(2')) aminoglycoside kinase family are unique in their ability to utilize GTP as a cofactor for antibiotic modification. Here we describe the structural determinants for GTP recognition in these enzymes. The crystal structure of the GTP-dependent APH(2')-IIIa shows that although this enzyme has templates for both ATP and GTP binding superimposed on a single nucleotide specificity motif, access to the ATP-binding template is blocked by a bulky tyrosine residue. Substitution of this tyrosine by a smaller amino acid opens access to the ATP template. Similar GTP binding templates are conserved in other bacterial aminoglycoside kinases, whereas in the structurally related eukaryotic protein kinases this template is less conserved. The aminoglycoside kinases are important antibiotic resistance enzymes in bacteria, whose wide dissemination severely limits available therapeutic options, and the GTP binding templates could be exploited as new, previously unexplored targets for inhibitors of these clinically important enzymes.     

Wild type N-ras displays anti-malignant properties, in part by downregulating decorin

Previously, we have shown that wild type N-ras (wt N-ras) harbors an anti-malignant effect against mutated Ras and in tumors without Ras mutations. To investigate the molecular bases of this anti-malignant activity, we have studied the potency of this anti-malignant effect in a model system against SV40 large T antigen (SV40T). We show that wild-type N-ras (wt N-ras) counteracts the effects of SV40T in NIH3T3 cells as seen by a decrease in proliferation, anchorage independence and changes in migration. We also show that wt N-ras elicits the same anti-malignant effects in some human tumor cell lines (HT1080 and MDA-MB-231). Through mRNA and microRNA (miRNAs) expression profiling we have identified genes (decorin) and miRNAs (mir-29A, let-7b) modulated by wt N-ras potentially responsible for the anti-malignant effect. Wt N-ras appears to mediate its anti-malignant effect by downregulating some of the targets of the TGFβ pathway and decorin, which are able to reverse the inhibition of migration induced by wt N-ras. Our experiments show that the molecules that mediate the anti-malignant effect by wt N-ras appear to be different from those modulated by transforming N-ras. The components of the pathways modulated by wt N-ras mediating its anti-malignant effects are potential targets for therapeutic intervention in cancer.