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The piggyBac transposable element was successfully used for generation of the transgenic silkworm, Bombyx mori. The EGFP was adopted in this study as a screening marker in transgenic vector under the control of an artificial promoter containing Pax-6 binding sites that can drive eye-specific genes expression in various insect species including B. mori and Drosophila. 111 independent transgenic lines were obtained among 700 fertile G0 moths. Most of the transgenic lines contained two or more chromosomal insertions of the EGFP marker, which were stably inherited over more than six generations during the time of this project. PiggyBac-mediated transposition was confirmed by identifying the characteristic TTAA duplication sequence at the insertion sites. The stable and high efficient transmission of a genetic marker into B. mori confirms the usage of this vector-marker system for industrial production and theoretical research. [ABSTRACT FROM AUTHOR]

Abstract Robust speed control of a low damped electromechanical system with backlash is studied, controlled load angular speed being not measured. The proposed control strategy combines a Luenberger observer (load angular speed and load torque disturbance estimations) and a robust CRONE controller. The observer provides estimation of the load angular speed and of the disturbance torque applied on the load. Through the computation of only three independent parameters (as many as a PID controller), the CRONE controller permits to ensure the robust speed control of the load in spite of plant parametric variations and speed observation errors. The proposed control strategy is applied to a four mass experimental test bench. [ABSTRACT FROM AUTHOR]

We have developed a system for stable germline transformation in the silkworm Bombyx mori L. using piggyBac, a transposon discovered in the lepidopteran Trichoplusia ni. The transformation constructs consist of the piggyBac inverted terminal repeats flanking a fusion of the B. mori cytoplasmic actin gene BmA3 promoter and the green fluorescent protein (GFP). A nonautonomous helper plasmid encodes the piggyBac transposase. The reporter gene construct was coinjected into preblastoderm eggs of two strains of B. mori. Approximately 2% of the individuals in the G1 broods expressed GFP. DNA analyses of GFP-positive G1 silkworms revealed that multiple independent insertions occurred frequently. The trans-gene was stably transferred to the next generation through normal Mendelian inheritance. The presence of the inverted terminal repeats of piggyBac and the characteristic TTAA sequence at the borders of all the analyzed inserts confirmed that transformation resulted from precise transposition events. This efficient method of stable gene transfer in a lepidopteran insect opens the way for promising basic research and biotechnological applications. [ABSTRACT FROM AUTHOR]