1,721,055 research outputs found
Induction of Malathion resistance in CCE/CC128 cell line of Mediterranean fruit fly (Ceratitis capitata (Wied.))(Diptera: Tephritidae)
No full textThe CCE/CC128 cell line, derived from fertilized eggs of theMediterranean fruit fly (Ceratitis capitata), was used toinvestigate whether insect cells in culture could developresistance to Malathion. After 20 cycles of pulse-chasetreatment (28 h exposure to 90 μg/ml of Malathion and 48 hrecovery in normal medium), a Mal 90 selected population wasobtained. DNA content analysis showed that the values were distributed between levels 2C and 4C and no accumulation ofcells in a specific phase of the cell cycle was observed.Furthermore, preliminary molecular analysis showed noamplification of the esterase gene in resistant cells.Cross-resistance of Mal 90 cells towards other insecticides wasassayed and found to be absent. Our data support the idea thatthe medfly cell line and, more generally, insect cell cultures,could represent a promising system to investigate insecticideresistance mechanisms
Malathion resistance in CCE/CC128 cell line of Mediterranean Fruit Fly, Ceratitis capitata (Diptera:Tephritidae)
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Aphidicolin-induced fragile sites in Chinese hamster cells. Relationship with telomere-related sequences
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Non inducibilità di resistenza al Malathion in cellule della linea stabilizzata CCE/CC128 di Ceratitis capitata Wied. (Diptera: Tephitidae)
No full textSpontaneous and aphidicolin-sensitive fragile site 3cen co-localizes with the (TTAGGG)n telomeric sequence in Chinese hamster cells
No full textAphidicolin-sensitive fragile sites were analyzed in immortalized Chinese hamster embryonal fibroblast cells (CHEF18) at three different passages along their spontaneous progression toward tumorigenicity. Five fragile sites (viz., 12q22, 3cen, 3p21, 3q31, and Xq21) were detected. Three of these sites carry spontaneous aberrations and are thus regions of chromosomal instability; however, they were not involved in the formation of the clonal rearrangements that are characteristic of CHEF 18 cells. The presence of the (TTAGGG)n telomeric sequence in chromosome bands associated with fragile sites was investigated using fluorescence in situ hybridization and primed in situ labeling. A common location of fragile sites and telomeric sequence was found at the centromere of chromosome 3
Development of insecticide resistance in an established cell line of Mediterranean Fruit Fly (Ceratitis capitata Wied.) (Diptera: Tephritidae)
No full textCaratterizzazione del P450 1A1 indotto da beta-naphtoflavone nella spigola (Dicentrarchus labrax): RT-PCR e sequenziamento
No full textA method for prediction of accessible sites on an mRNA sequence for target selection of hammehead ribozymes
No full textHammerhead ribozymes are short RNA molecules endowed with endoribonucleolytic activity. Their use as molecular tools for specific inhibition of gene translation is affected by many factors including the target accessibility. A method for the prediction of accessible target sites for hammerhead ribozymes within a given RNA sequence is described. This method maps all putative NUH cleavage sites (N = A, C, G, U and H = A, C, U) and picks out short flanking regions as the binding domain for the corresponding ribozyme. The probabilistic level of unfolding, accessibility score (AS), is then calculated for each target region on the basis of a comparison of all folding structures obtained for the target RNA and arranged according to the Boltzmann's distribution. At the end, a series of imposed limits gives the best target sequences endowed with highly probable accessibility and with a potentially active catalytic structure of the hammerhead sequence. A successive experimental approach to verify the effective accessibility of selected targets was used. For that, antisense oligonucleotides addressed to the coding region of bcl2 mRNA were synthesized and administered to the MCF7 human cell line. The inhibition of gene expression, as measured by western analysis of the BCL2 protein, demonstrated that all target sites selected on the basis of their putative accessibility were actually sensitive to antisense treatments while the inaccessible ones were not. The application of this target discovery method to ribozyme design is proposed in order to satisfy a crucial condition
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