640 research outputs found
Selezione di razze di Bombyx mori ad alta efficienza nutrizionale e relative problematiche
Get PDFThe silkworm (Bombyx mori L.) is an insect belonging to the lepidopteran order, family Bombycidae: it is one of the two unique species belonging to the genus Bombyx, together with its ancestor – Bombyx mandarina Moore. In the past, silkworm exploitation in Europe was particularly related to the agricultural sector and the production of the silk thread but this type of activity has being disappearing from the old continent, in favour of some Asian countries, especially China, where cost of labour is low. In spite of the decline of these traditional activities the silkworm started to be used as a tool in a lot of technological applications and as a model in scientific research in various fields. Silk is regarded as a promising biomaterial because of its physical and chemical features both on the macro and microscale as well as in nano-technologies. Furthermore biology and biotechnology are interested in silkworm, or in its cell cultures, as a bioreactor to produce recombinant proteins which should otherwise be produced in bacteria or yeasts. The silkworm has a suitable size even for complex experiments with respect to other organisms used for the same aims, however it does not require large rearing rooms or high quantity of food, it can be easily reared under controlled conditions and its biological cycle is short (it lasts about 45 days), representing thus, also a model for basic research in life sciences. Moreover, to use the silkworm as a technological platform, important steps were achieved by sequencing the whole genome and by developing new optimized artificial diets for this insect (strictly monophagous), which freed rearing from seasonal constraints coming from mulberry leaf production in temperate climates. Thus, the above-mentioned new potentialities and a revived interest from the textile industry, about a silk supply chain outside Asia, establish the background of the research work described in this thesis. In fact, performed experiments relate with relaunching basic research activities about B. mori and aimed at meeting the needs of a silk industry, possibly developing in temperate countries. The starting material, that is the B. mori strains, belongs to the germplasm collection of Consiglio per la Ricerca e la sperimentazione in Agricoltura – Unità di ricerca di Apicoltura e Bachicoltura (CRA-API) of Padua and consists of about 200 strains, which differ in their phenotypic and genotypic characteristics. From the aforementioned collection, a selection process based on a mixed rearing strategy on both mulberry leaves and artificial diet has been started. The final goal was to select new strains characterized by high nutritional efficiency in order to optimize the cost-benefit ratio in all those application oriented to productivity. As already stated selection was based on a mixed approach: the first and more traditional step consisted in rearing silkworm larvae on mulberry leaf without any limitation in its quantity, by selecting only for the most important commercial parameters. On the other hand, the second step was a rearing cycle on artificial diet with a limited food amount fed to fifth instar larvae, followed by a selection process according to the most important productive traits. After three years and six generations of selection and genetic improvement, the obtained strains were compared among each other and with the unselected populations on the base of nutritional indexes which permitted an assessment of their conversion efficiency of proteins contained in the food matrix to body mass and silk. The final evaluation allowed to highlight the efficacy of the adopted strategy in selecting the desired features, although a difference related to diverse adaptability of the strains to the diet was recorded. In particular, for some of them, an additional preparatory step of selection on diet appears to be appropriate. During the period when experiments aimed at selection of highly efficient strains were performed, other relevant experimental data were produced. First of all, a new micro-organism which proved itself to be pathogenic for the silkworm reared on artificial diet was isolated and characterized; then, in-depth measurements about cold hardiness of eggs of a polyvoltine silkworm strain belonging to CRA-API’s collection were carried out. Described results to date do not represent the final goal but, an intermediate stage of a selection process that will continue at CRA-API and also, the starting point for the production of new hybrids with improved performances and suited to be reared on both mulberry leaf and artificialdiet
An Efficient Workflow for Screening and Stabilizing CRISPR/Cas9-Mediated Mutant Lines in Bombyx mori
Get PDFThe domestic silkworm Bombyx mori is extensively studied as a model organism for lepidopteran genetics and has an economic value in silk production. Silkworms also have applications in biomedical and cosmetic industries, and the production of mutant B. mori strains significantly enhances basic and applied silkworm research. In recent years, CRISPR/Cas9 technology is being rapidly adopted as the most efficient molecular tool for generating silkworm lines carrying mutations in target genes. Here we illustrate a complete and efficient workflow to screen, characterize rapidly and follow mutations through generations, allowing the generation of B. mori lines, stably inheriting single CRISPR/Cas9-induced mutations. This approach relies on the use of different molecular methods, the heteroduplex assay, cloning followed by Sanger sequencing, and the amplification refractory mutation system PCR. The use of these methodologies in a sequential combination allows the identification of CRISPR/Cas9-induced mutations in genes mapping on both autosomes and sex chromosomes, and the selection of appropriate individuals to found stable mutant B. mori lines. This protocol could be further applied to screen CRISPR/Cas9 mutations in haploid insects
Silkworm and Silk: Traditional and Innovative Applications
Get PDFThe various subjects covered in the present Special Issue “Silkworm and Silk: Traditional and Innovative Applications” demonstrate how sericulture, a practice deeply rooted in human history, can act as a bridge to bring together an exceptionally wide range of scientific and technical expertise in both conventional topics and cutting-edge technologies [...
Determinaion of 1-deoxynojirimicin (DNJ) in mulberry leaves (Morus app. L.), silkworms and silk by HPLC-TQ-MS
No full textIntroduction
DNJ is a constituent of mulberry leaves and when consumed as part of the diet it showed beneficial properties on health: suppression of high blood glucose levels, antibacterial and antiviral activities [1,2]. In this work DNJ content in different matrices was investigated, the importance lies in the potential uses of these products as food and feed, nutraceutical and medical device.
Methods
Twenty-nine samples of mulberry leaves from an experimental field (CREA-Padova), silk worms larvae and silk cocoons were analyzed by HILIC technique. EtOH:H2O 50% solution and water 60° were employed for leaves extraction. Grinded cocoons and freeze-dried larvae were extracted with EtOH:H2O 50% (at 60°C for cocoons). The detection was performed by using ESI in positive ion MRM mode.
Results
The optimized mass conditions allowed the identification of three usable transitions (one for the quantification of DNJ 164.1146.1, others as qualifier ions 164.1128.1, 164.1110.1). DNJ was detected in all the considered matrices and determined by using its calibration curve (r2=0.9865). In the case of leaves, water infusion resulted less efficient with respect to EtOH:H2O extraction. The mean concentration value in leaves obtained with infusion is 0.073±0.004 mg/g while 2.56±0.3 mg/g for extracts. The mean concentration recovered in larvae is 0.034±0.001 mg/g whereas substantially lower amounts were obtained for silk (3.12*10-5 mg/g).
Conclusions
In this work an efficient HPLC-TQ-MS method was applied to the determination of DNJ in leaves, larvae and silk. The study showed that Morus nigra L. presents the highest content among the tested species and that DNJ is detectable also in larvae and silk. These results could be useful in the further development of herbal supplements and for the potential use of larvae as medicated feed or functional food
A Bombyx mori Infection Model for Screening Antibiotics against Staphylococcus epidermidis
Get PDFThe increasing number of microorganisms that are resistant to antibiotics is prompting the development of new antimicrobial compounds and strategies to fight bacterial infections. The use of insects to screen and test new drugs is increasingly considered a promising tool to accelerate the discovery phase and limit the use of mammalians. In this study, we used for the first time the silkworm, Bombyx mori, as an in vivo infection model to test the efficacy of three glycopeptide antibiotics (GPAs), against the nosocomial pathogen Staphylococcus epidermidis. To reproduce the human physiological temperature, the bacterial infection was performed at 37 °C and it was monitored over time by evaluating the survival rate of the larvae, as well the response of immunological markers (i.e., activity of hemocytes, activation of the prophenoloxidase system, and lysozyme activity). All the three GPAs tested (vancomycin, teicoplanin, and dalbavancin) were effective in curing infected larvae, significantly reducing their mortality and blocking the activation of the immune system. These results corroborate the use of this silkworm infection model for the in vivo studies of antimicrobial molecules active against staphylococci
Bibliometric Analysis of Trends in Mulberry and Silkworm Research on the Production of Silk and Its By-Products
Get PDFSIMPLE SUMMARY: Over the past two decades scientific research on sericulture, the agricultural activity of silk production, generated a great number of outputs in the form of articles reported and classified by one of the most well-known and used database dealing with scientific literature. This occurrence demonstrates an increasing interest in this sector especially starting from 2000s; results presented in relevant papers showed their applicability even in fields apparently not related to silk production as commonly meant, like medicine, cosmetics, and engineering. To understand how sericulture has been transcending its usual boundaries, which are its current “hotspots”, and links with other fields of study, the authors propose a text-mining based analysis of the outputs of scientific research on sericulture and silk; the final goal is to establish “quantitative” indicators for researchers, entrepreneurs, and scholars. ABSTRACT: Traditionally, sericulture is meant as the agricultural activity of silk production, from mulberry (Morus sp.pl.) cultivation to silkworm (Bombyx mori L.) rearing. The aim of the present work is to analyze the trends and outputs of scientific research on sericulture-related topics during the last two decades, from 2000 to 2020. In this work the authors propose a text-mining analysis of the titles, abstracts and keywords of scientific articles focused on sericulture and available in the SCOPUS database considering the above-mentioned period of time; from this article collection, the 100 most recurrent terms were extracted and studied in detail. The number of publications per year in sericulture-related topics increased from 87 in 2000 to 363 in 2020 (+317%). The 100 most recurrent terms were then aggregated in clusters. The analysis shows how in the last period scientific research, besides the traditional themes of sericulture, also focused on alternative products obtainable from the sericultural practice, as fruits of mulberry trees (increment of +134% of the occurrences in the last five years) and chemical compounds as antioxidants (+233% of occurrences), phenolics (+330% of occurrences) and flavonoids (+274% of occurrences). From these considerations, the authors can state how sericulture is an active and multidisciplinary research field
Remote Sensing Imaging as a Tool to Support Mulberry Cultivation for Silk Production
Get PDFIn recent decades there has been an increasing use of remotely sensed data for precision agricultural purposes. Sericulture, the activity of rearing silkworm (Bombyx mori L.) larvae to produce silk in the form of cocoons, is an agricultural practice that has rarely used remote sensing techniques but that could benefit from them. The aim of this work was to investigate the possibility of using satellite imaging in order to monitor leaf harvesting in mulberry (Morus alba L.) plants cultivated for feeding silkworms; additionally, quantitative parameters on silk cocoon production were related to the analyses on vegetation indices. Adopting PlanetScope satellite images, four M. alba fields were monitored from the beginning of the silkworm rearing season until its end in 2020 and 2021. The results of our work showed that a decrease in the multispectral vegetation indices in the mulberry plots due to leaf harvesting was correlated with the different parameters of silk cocoons spun by silkworm larvae; in particular, a decrease in the Normalized Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) had high correlations with quantitative silk cocoon production parameters (R2 values up to 0.56, p < 0.05). These results led us to the conclusion that precision agriculture can improve sericultural practice, offering interesting solutions for estimating the quantity of produced silk cocoons through the remote analysis of mulberry fields
The Pottesman Collection in the British Museum. Early Dynastic and Sargonic administrative texts. With an Appendix on a Palmyrene Inscription
No full textEdizione, trascrizione, traduzione e commento di un frammento di iscrizione palmirena inedita presente nella collezione Pottesman del British Museum (Appendice Agostini).The British Museum houses a small collection of six cuneiform tablets and a Palmyrene dedicatory inscription purchased in 1987 from the private collection of Solomon Pottesman. The aim of the present contribution is to provide a catalog of this lot and an edition of the so far unpublished cuneiform texts. In the appendix, Alessio Agostini added the edition of the Palmyrene inscription, which would have otherwise gone beyond the capabilities of the present author
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