180 research outputs found
Sex and the single embryo: early deveopment in the Mediterranean fruit fly, Ceratitis capitata
Get PDF<p>Abstract</p> <p>Background</p> <p>In embryos the maternal-to-zygotic transition (MTZ) integrates post-transcriptional regulation of maternal transcripts with transcriptional activation of the zygotic genome. Although the molecular mechanisms underlying this event are being clarified in <it>Drosophila melanogaster</it>, little is know about the embryogenic processes in other insect species. The recent publication of expressed sequence tags (ESTs) from embryos of the global pest species <it>Ceratitis capitata </it>(medfly) has enabled the investigation of embryogenesis in this species and has allowed a comparison of the embryogenic processes in these two related dipteran species, <it>C. capitata </it>and <it>D. melanogaster</it>, that shared a common ancestor 80-100 mya.</p> <p>Results</p> <p>Using a novel PCR-based sexing method, which takes advantage of a putative LTR retrotransposon MITE insertion on the medfly Y chromosome, the transcriptomes of individual early male and female embryos were analysed using RT-PCR. This study is focused on two crucial aspects of the onset of embryonic development: sex determination and cellular blastoderm formation. Together with the three known medfly genes (<it>Cctransformer</it>, <it>Cctransformer2 </it>and <it>Ccdoublesex</it>), the expression patterns of other medfly genes that are similar to the <it>D. melanogaster </it>sex-determination genes (<it>sisterlessA, groucho, deadpan, Sex-lethal, female lethal d, sans fille </it>and <it>intersex</it>) and four cellular blastoderm formation genes (<it>Rho1, spaghetti squash, slow-as-molasses </it>and <it>serendipity-α</it>) were analyzed, allowing us to sketch a preliminary outline of the embryonic process in the medfly. Furthermore, a putative homologue of the <it>Zelda </it>gene has been considered, which in <it>D. melanogaster </it>encodes a DNA-binding factor responsible for the maternal-to-zygotic transition.</p> <p>Conclusions</p> <p>Our novel sexing method facilitates the study of i) when the MTZ transition occurs in males and females of <it>C. capitata</it>, ii) when and how the maternal information of "female-development" is reprogrammed in the embryos and iii) similarities and differences in the regulation of gene expression in <it>C. capitata </it>and <it>D. melanogaster</it>. We suggest a new model for the onset of the sex determination cascade in the medfly: the maternally inherited <it>Cctra </it>transcripts in the female embryos are insufficient to produce enough active protein to inhibit the male mode of <it>Cctra </it>splicing. The slow rate of development and the inefficiency of the splicing mechanism in the pre-cellular blastoderm facilitates the male-determining factor (M) activity, which probably acts by inhibiting CcTRA protein activity.</p
Laboratory calibration and field assessment of low-cost electrochemical Ozone sensors in Alpine and Arctic environments
Get PDFCalibration and assessment of electrochemical low-cost sensors in remote alpine harsh environments
Get PDFThis work presents results from an original open-source low-cost sensor (LCS) system developed to measure tropospheric O3 in a remote high altitude alpine site. Our study was conducted at the Col Margherita Observatory (2543 m above sea level), in the Italian Eastern Alps. The sensor system mounts three commercial low-cost O3/NO2 sensors that have been calibrated before field deployment against a laboratory standard (Thermo Scientific; 49i-PS), calibrated against the standard reference photometer no. 15 calibration scale of the World Meteorological Organization (WMO). Intra- and intercomparison between the sensors and a reference instrument (Thermo Scientific; 49c) have been conducted for 7 months from May to December 2018. The sensors required an individual calibration, both in laboratory and in the field. The sensor's dependence on the environmental meteorological variables has been considered and discussed. We showed that it is possible to reduce the bias of one LCS by using the average coefficient values of another LCS working in tandem, suggesting a way forward for the development of remote field calibration techniques. We showed that it is possible reconstruct the environmental ozone concentration during the loss of reference instrument data in situations caused by power outages. The evaluation of the analytical performances of this sensing system provides a limit of detection (LOD) 0.8, bias >3.5 ppb and ±8.5 at 95 % confidence. This first implementation of a LCS system in an alpine remote location demonstrated how to obtain valuable data from a low-cost instrument in a remote environment, opening new perspectives for the adoption of low-cost sensor networks in atmospheric sciences.publishedVersio
A survey of total gaseous mercury and ozone during spring and summer 2018 after characterization of air masses at the Col Margherita Atmospheric Observatory (2543 m a.s.l.) in the Italian Dolomites
Get PDFAtmospheric depositions of black carbon, inorganic pollutants and mineral dust from the Ortles, Eastern European Alps ice cores during the last 3000 years
Get PDFMosChito rafts as a promising biocontrol tool against larvae of the common house mosquito, Culex pipiens
Get PDFMosquito control is of paramount importance, in particular, in light of the major environmental alterations associated with human activities, from climate change to the altered distribution of pathogens, including those transmitted by Arthropods. Here, we used the common house mosquito, Culex pipiens to test the efficacy of MosChito raft, a novel tool for mosquito larval control. MosChito raft is a floating hydrogel matrix, composed of chitosan, genipin and yeast cells, as bio-attractants, developed for the delivery of a Bacillus thuringiensis israeliensis (Bti)-based bioinsecticide to mosquito larvae. To this aim, larvae of Cx. pipiens were collected in field in Northern Italy and a novel colony of mosquito species (hereafter: Trescore strain) was established. MosChito rafts, containing the Bti-based formulation, were tested on Cx. pipiens larvae from the Trescore strain to determine the doses to be used in successive experiments. Thus, bioassays with MosChito rafts were carried out under semi-field conditions, both on larvae from the Trescore strain and on pools of larvae collected from the field, at different developmental stages. Our results showed that MosChito raft is effective against Cx. pipiens. In particular, the observed mortality was over 50% after two days exposure of the larvae to MosChito rafts, and over 70-80% at days three to four, in both laboratory and wild larvae. In conclusion, our results point to the MosChito raft as a promising tool for the eco-friendly control of a mosquito species that is not only a nuisance insect but is also an important vector of diseases affecting humans and animals
Chimeric symbionts expressing a Wolbachia protein stimulate mosquito immunity and inhibit filarial parasite development
Get PDFWolbachia can reduce the capability of mosquitoes to transmit infectious diseases to humans and is currently exploited in campaigns for the control of arboviruses, like dengue and Zika. Under the assumption that Wolbachia-mediated activation of insect immunity plays a role in the reduction of mosquito vectorial capacity, we focused our attention on the Wolbachia surface protein (WSP), a potential inductor of innate immunity. We hypothesized that the heterologous expression of this protein in gut- and tissue-associated symbionts may reduce parasite transmission. We thus engineered the mosquito bacterial symbiont Asaia to express WSP (AsaiaWSP). AsaiaWSP induced activation of the host immune response in Aedes aegypti and Anopheles stephensi mosquitoes, and inhibited the development of the heartworm parasite Dirofilaria immitis in Ae. aegypti. These results consolidate previous evidence on the immune-stimulating property of WSP and make AsaiaWSP worth of further investigations as a potential tool for the control of mosquito-borne diseases
Increasing the maturity of measurements of essential climate variables (ECVs) at Italian atmospheric WMO/GAW observatories by implementing automated data elaboration chains
Get PDFIn the framework of the National Project of Interest NextData, we developed automatic procedures for the flagging and formatting of trace gases, atmospheric aerosols and meteorological data to be submitted to the World Data Centers (WDCs) of the Global Atmosphere Watch program of the World Meteorological Organization (WMO/GAW). In particular, the atmospheric Essential Climate Variables (ECVs) covered in this work are observations of near-surface trace gas concentrations, aerosol properties and meteorological variables, which are under the umbrella of the World Data Center for Greenhouse Gases (WDCGG), the World Data Center for Reactive Gases, and the World Data Center for Aerosol (WDCRG and WDCA). We developed an overarching processing chain to create a number of data products (data files and reports) starting from the raw data, finally contributing to increase the maturity of these measurements. To this aim, we implemented specific routines for data filtering, flagging, format harmonization, and creation of data products, useful for detecting instrumental problems, particular atmospheric events and quick data dissemination towards stakeholders or citizens. Currently, the automatic data processing is active for a subset of ECVs at 5 measurement sites in Italy. The system represents a valuable tool to facilitate data originators towards a more efficient data production. Our effort is expected to accelerate the process of data submission to WMO/GAW or to other reference data centers or repositories. Moreover, the adoption of automatic procedures for data flagging and data correction allows to keep track of the process that led to the final validated data, and makes data evaluation and revisions more efficient by improving the traceability of the data production process
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