Environmental tuning of an insect ensemble: The tenebrionid beetles inhabiting a Mediterranean coastal dune zonation

Few studies have investigated insect ensembles, i.e. phylogenetically bounded groups of species that use a similar set of resources within a community. The zonation of dune vegetation makes these ecosystems ideal for the study of insect ensembles in a short space. In this study, we investigated if the tenebrionid beetles forming an ensemble on a dune zonation showed variations in community organization (relative abundances and species diversity) in different but spatially associated biotopes defined by different plant communities. Three biotopes (corresponding to European Commission habitat 2110, 2120 and 2230) of a well-preserved Mediterranean dune were sampled using square plots of 2 × 2 m at three places. To investigate if there was some association between species and habitat we applied a χ² test. Variations in community structure parameters were investigated using Shannon index. The three biotopes host tenebrionid communities with similar species composition and overall abundances, confirming that they form a single ensemble. However, tenebrionid species are differently associated with different biotopes along the zonation, with some species occurring with different proportions among the biotopes. A local selection process can be postulated as a mechanism responsible for these differences.     

Genetic susceptibility to malignant pleural mesothelioma and other asbestos-associated diseases

Exposure to asbestos fibers is a major risk factor for malignant pleural mesothelioma (MPM), lung cancer, and other non-neoplastic conditions, such as asbestosis and pleural plaques. However, in the last decade many studies have shown that polymorphism in the genes involved in xenobiotic and oxidative metabolism or in DNA repair processes may play an important role in the etiology and pathogenesis of these diseases. To evaluate the association between diseases linked to asbestos and genetic variability we performed a review of studies on this topic included in the PubMed database. One hundred fifty-nine citations were retrieved; 24 of them met the inclusion criteria and were evaluated in the review. The most commonly studied GSTM1 polymorphism showed for all asbestos-linked diseases an increased risk in association with the null genotype, possibly linked to its role in the conjugation of reactive oxygen species. Studies focused on GSTT1 null and SOD2 Ala16Val polymorphisms gave conflicting results, while promising results came from studies on alpha1-antitrypsin in asbestosis and MPO in lung cancer. Among genetic polymorphisms associated to the risk of MPM, the GSTM1 null genotype and two variant alleles of XRCC1 and XRCC3 showed increased risks in a subset of studies. Results for the NAT2 acetylator status, SOD2 polymorphism and EPHX activity were conflicting. Major limitations in the study design, including the small size of study groups, affected the reliability of these studies. Technical improvements such as the use of high-throughput techniques will help to identify molecular pathways regulated by candidate genes.     

A grapevine (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L.) genetic map integrating the position of 139 expressed genes

Grapevine molecular maps based on microsatellites, AFLP and RAPD markers are now available. SSRs are essential to allow cross-talks between maps, thus upgrading any growing grapevine maps. In this work, single nucleotide polymorphisms (SNPs) were developed from coding sequences and from unique BAC-end sequences, and nested in a SSR framework map of grapevine. Genes participating to flavonoids metabolism and defence, and signal transduction pathways related genes were also considered. Primer pairs for 351 loci were developed from ESTs present on public databases and screened for polymorphism in the “Merzling” (a complex genotype Freiburg 993–60 derived from multiple crosses also involving wild Vitis species) × Vitis vinifera (cv. Teroldego) cross population. In total 138 SNPs, 108 SSR markers and a phenotypic trait (berry colour) were mapped in 19 major linkage groups of the consensus map. In specific cases, ESTs with putatively related functions mapped near QTLs previously identified for resistance and berry ripening. Genes related to anthocyanin metabolism mapped in different linkage groups. A myb gene, which has been correlated with anthocyanin biosynthesis, cosegregated with berry colour on linkage group 2. The possibility of associating candidate genes to known position of QTL is discussed for this plant. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Marzia Salmaso and Giulia Malacarne contributed equally to the present work.     

The GPI-anchored CD52 antigen of the sperm surface interacts with semenogelin and participates in clot formation and liquefaction of human semen

CD52 is a human glycosylphosphatidylinositol (GPI)-anchored antigen exclusively expressed in leukocytes and epididymal cells. It is also present in sperm, being inserted in their plasma membrane as they pass through the epididymis. In a previous paper we identified a new CD52 form without GPI anchor by fast performance liquid chromatography (FPLC) fractionation of semen components. The form has a lower negative charge than the GPI-anchored form and occurs as the only CD52 form in prostasome-free seminal plasma. It was also found associated with the ejaculated sperm, but in contrast to the GPI-anchored one, it is lost during the capacitation process. In this paper we indicate that (1) the GPI-anchored CD52 of the sperm surface serves as receptor for semenogelin I during clot formation, (2) liquefaction involves cleavage of the GPI anchor from certain CD52 molecules, releasing sperm from the clot and the soluble antigen bound to semenogelin fragments into the seminal plasma and (3) the clot is a sponge-like structure housing sperm. Soluble CD52 was immunopurified from the soluble CD52-containing FPLC fraction using CAMPATH-1G and was found to be complexed with a semenogelin-derived peptide of the carboxyl terminal portion of semenogelin I, having the sequence SQTEKLVAGKQI and starting from amino acid 376. Immunoprecipitation and immunoblot analyses using CAMPATH-1G and anti-semenogelin as immunoprecipitating antibodies and anti-gp20 and anti-semenogelin as immunoblot detectors of the corresponding antigens, confirmed that the soluble CD52 formed a complex with semenogelin. The semenogelin-CD52 soluble form was found to be a direct consequence of the liquefaction process since only the GPI-anchored CD52 was recovered in uniquefied semen after recovering sperm and seminal plasma by urea solubilization of the clot.     

Independent influence of insulin, catecholamines, and thyroid hormones on metabolic syndrome

The objective of this study was to examine whether metabolic syndrome, defined according to adult treatment panel III criteria, is associated with insulin, catecholamines, and thyroid hormones, independently of age and gender. A cohort of 651 euthyroid overweight and obese patients, 440 women and 211 men, aged 18-68 years, were examined. Central fat accumulation (indirectly measured by waist circumference), fasting thyroid-stimulating hormone (TSH), FT(3), FT(4), insulin, glucose, and lipid (cholesterol, HDL-cholesterol, and triglyceride) serum concentrations, 24-h urinary catecholamines, and the level of insulin resistance (estimated by homeostasis model assessment for insulin resistance (HOMA(IR))) were measured. Patients with metabolic syndrome showed higher insulin (P < 0.001) and FT(3) (P < 0.001) serum levels and higher 24-h urinary noradrenaline (P < 0.001) than subjects without this syndrome. The number of metabolic syndrome parameters was directly associated with insulin (P < 0.001) and FT(3) (P < 0.05) serum levels, and with 24-h urinary noradrenaline (P < 0.001) in the whole population. When a multiple regression analysis was performed with the metabolic syndrome as the dependent variable, and age, gender, and insulin, and TSH, FT(3), FT(4) serum levels, and 24-h urinary noradrenaline and adrenaline as independent variables, the metabolic syndrome maintained an independent positive association with age (P < 0.001), male sex (P < 0.001), insulin (P < 0.001), and 24-h urinary noradrenaline (P < 0.001). In conclusion, this study suggests that insulin and noradrenaline cooperate independently to the development of the metabolic syndrome.     

The N-Terminal Domain of ERK1 Accounts for the Functional Differences with ERK2

The Extracellular Regulated Kinase 1 and 2 transduce a variety of extracellular stimuli regulating processes as diverse as proliferation, differentiation and synaptic plasticity. Once activated in the cytoplasm, ERK1 and ERK2 translocate into the nucleus and interact with nuclear substrates to induce specific programs of gene expression. ERK1/2 share 85% of aminoacid identity and all known functional domains and thence they have been considered functionally equivalent until recent studies found that the ablation of either ERK1 or ERK2 causes dramatically different phenotypes. To search a molecular justification of this dichotomy we investigated whether the different functions of ERK1 and 2 might depend on the properties of their cytoplasmic-nuclear trafficking. Since in the nucleus ERK1/2 is predominantly inactivated, the maintenance of a constant level of nuclear activity requires continuous shuttling of activated protein from the cytoplasm. For this reason, different nuclear-cytoplasmic trafficking of ERK1 and 2 would cause a differential signalling capability. We have characterised the trafficking of fluorescently tagged ERK1 and ERK2 by means of time-lapse imaging in living cells. Surprisingly, we found that ERK1 shuttles between the nucleus and cytoplasm at a much slower rate than ERK2. This difference is caused by a domain of ERK1 located at its N-terminus since the progressive deletion of these residues converted the shuttling features of ERK1 into those of ERK2. Conversely, the fusion of this ERK1 sequence at the N-terminus of ERK2 slowed down its shuttling to a similar value found for ERK1. Finally, computational, biochemical and cellular studies indicated that the reduced nuclear shuttling of ERK1 causes a strong reduction of its nuclear phosphorylation compared to ERK2, leading to a reduced capability of ERK1 to carry proliferative signals to the nucleus. This mechanism significantly contributes to the differential ability of ERK1 and 2 to generate an overall signalling output.     

Differential screening of phage-ab libraries by oligonucleotide microarray technology

A novel and efficient tagArray technology was developed that allows rapid identification of antibodies which bind to receptors with a specific expression profile, in the absence of biological information. This method is based on the cloning of a specific, short nucleotide sequence (tag) in the phagemid coding for each phage-displayed antibody fragment (phage-Ab) present in a library. In order to set up and validate the method we identified about 10,000 different phage-Abs binding to receptors expressed in their native form on the cell surface (10 k Membranome collection) and tagged each individual phage-Ab. The frequency of each phage-Ab in a given population can at this point be inferred by measuring the frequency of its associated tag sequence through standard DNA hybridization methods. Using tiny amounts of biological samples we identified phage-Abs binding to receptors preferentially expressed on primary tumor cells rather than on cells obtained from matched normal tissues. These antibodies inhibited cell proliferation in vitro and tumor development in vivo, thus representing therapeutic lead candidates.     

A PCR-based diagnostic tool for distinguishing grape skin color mutants

Berry skin color mutants are phenotypically different from their original cultivars, but they show identical molecular profile if analysed by using microsatellite markers. This work gives an easy, inexpensive and quick diagnostic tool to discriminate these somatic variants. We distinguished some grape (Vitis vinifera L.) skin color mutants from white to red or pink and from black to grey, pink or white and we investigated their molecular bases by single-strand conformational polymorphism (SSCP), single base primer extension and coding sequence analysis of anthocyanin biosynthetic enzyme genes and by polymerase chain reaction (PCR) analysis of VvmybA1 regulatory gene. Analyses of structural genes did not reveal polymorphisms between wild type and mutant cultivars but only among different varieties, whereas the study of VvmybA1 regulatory gene has given important outcomes for color mutants characterisation. The discrimination between white wild type and its derived colored mutant and between black wild type and white mutant has been obtained through a simple test of amplification for presence/absence. The discrimination between black wild type and less colored mutant has occurred through a quantitative result on agarose gel confirmed by real-time PCR analysis: the amount of functional allele in less colored somatic variants genome was about one-fourth of the correspondent quantity in original black cultivars genome.