Targeting ie-1 gene by RNAi induces baculoviral resistance in lepidopteran cell lines and in transgenic silkworms

RNA interference (RNAi)-mediated viral inhibition has been used in a few organisms for eliciting viral resistance. In the present study, we report the use of RNAi in preventing baculovirus infection in a lepidopteran. We targeted the baculoviral immediate early-1 (ie-1) gene in both a transformed lepidopteran cell line and in the transgenic silkworm Bombyx mori L. Constitutive expression of double-stranded RNA was achieved by piggyBac-mediated transformation of Sf9 cell line with a transgene encoding double-stranded ie-1 RNA (dsie-1). Strong viral repression was seen at early stages of infection but subsequent recovery of viral proliferation was observed. In contrast, the same transgene inserted into the chromosomes of transgenic silkworms induced long-term inhibition of B. mori nucleopolyhedrovirus infection, with nearly 40% protection compared with nontransgenic animals. Protection was efficient at larval stages after oral infection with occlusion bodies or hemocoel injection of budded viruses. Virus injected pupae also displayed resistance. These results show that heritable RNAi can be used to protect silkworm strains from baculovirus infection

L'Unité nationale séricicole

Chavancy Gérard. L'Unité nationale séricicole. In: Le Monde alpin et rhodanien. Revue régionale d'ethnologie, n°2-3/1991. Les filières de la soie lyonnaise, sous la direction de Florence Charpigny . pp. 129-130

Les Carnets de la soie

Chavancy (Gérard) and Marié (Michel). — Les Carnets de la soie (The silk notebooks). The authors, a researcher in biology and a film director, present the project of an «ail public» film, made up of four separate parts. «La laine des arbres» (The wool of trees) is about the origins of silk and associated legends ; «Le fil du temps •> (The Thread of Time), describes, in time and space, the long process that transforms thread into silk fabrics ; «L'art de la soie» (The art of silk) gives the creators the possibility to talk about their passion for silk ; <• Le ver à soie : profession modèle » (The silkworm : a model profession) présents biological research carried out thanks to the silkworm, a laboratory animal. Le Monde alpin et rhodanien, 2-3e trimestres 1991, Les filières de la soie lyonnaise, pp. 149 à 154.Chavancy (Gérard) et Marié (Michel). — Les Carnets de la soie. Les auteurs, un chercheur en biologie et un cinéaste, présentent le projet d'un film «tout public», conçu en quatre parties autonomes. «La laine des arbres» évoque les origines de la soie et les légendes qui y sont attachées ; «Le fil du temps» décrit, dans le temps et dans l'espace, le long processus qui transforme le fil en étoffe ; «L 'art de la soie» donne la parole aux créateurs qui évoquent leur passion pour la soie ; «Le ver à soie : profession modèle» présente les recherches biologiques menées grâce au ver à soie, animal de laboratoire. Le Monde alpin et rhodanien, 2-3e trimestres 1991, Les filières de la soie lyonnaise, pp. 149 à 154.Chavancy Gérard, Marié Michel. Les Carnets de la soie. In: Le Monde alpin et rhodanien. Revue régionale d'ethnologie, n°2-3/1991. Les filières de la soie lyonnaise, sous la direction de Florence Charpigny . pp. 149-154

Evaluation de la motorisation intermédiaire dans le cadre du projet "Mali Sud" : 21 novembre - 12 décembre 1982

L'opération de motorisation intermédiaire entreprise depuis 1977 au Mali correspond jusqu'alors à une phase de prévulgarisation. Techniquement, l'expérience peut-être considérée comme positive. Pour sa poursuite, deux voies nouvelles sont possibles: - faire supporter aux paysans l'intégralité des frais de l'opération, mais il est à craindre que les recherches d'économie immédiate ne la condamne techniquement, avant de connaitre le résultat financier octroyer une subvention au titre des matériels et de l'encadrement, comme ce fut le cas pour le lancement de la culture attelée pendant une trentaine d'années. Mais ces voies impliquent des actions d'organisation du suivi de l'opération par la mise en place d'une comptabilité analytique et la formation de mécaniciens susceptibles de la relayer pour la maintenance des matériel

A helium burst biolistic device adapted to penetrate fragile insect tissues

To compensate for the extremely low penetration efficiency of the original PDS/1000-He Bio Rad biolisticreg; device and the deleterious blast effect, design modifications have been made to the launching module. These modifications were evaluated on Bombyx mori embryos and fragile tissues, such as oocytes and imaginal wing disks. The original floppy macrocarrier was replaced by a rigid macrocarrier to avoid the effects of the helium blast. The efficiency of the gene gun bombardment was reinforced by the addition of a focusing nozzle. The reduced blast effect allowed us to carry out high-pressure shootings to small organs with improved penetration. This system allowed potentially all the internal embryonic tissues to be transfected with optimal survival rates. The new module was effective on tissues that are difficult to transfect, such as the epithelial wing disk that is covered by a peripodial membrane, and the ovarian follicle cells that lie under the ovariole cell membrane. The new macrocarrier allowed both an aqueous delivery of particles and an ethanolic dry delivery. No significant differences were noted between these two modes of delivery. The major improvement is the possibility of high pressure shooting correlated with appreciable penetration and a weak blast effect

Effect of tRNA pool balance on rate and uniformity of elongation during translation of fibroin mRNA in a reticulocyte cell-free system

Unsuccessful attempts to synthesize complete fibroin chains in vitro were previously made in heterologous cell-free system [3]. In the present work, we succeeded to obtain complete translation of purified fibroin mRNA in a rabbit reticulocyte lysate. Whilst this work was being completed [1], similar results were published by Lizardi et al. [4]. The synthesis of full-sized molecules of fibroin (M.W. 360,000) was achieved by adding tRNA from the posterior silk gland to the cell-free system. With tRNA from other sources, both the translation rate and the amount of complete fibroin chains dropped. This effect of tRNA is situated at the elongation level. Analysis of cell-free synthesized products by polyacrylamide gel electrophoresis shows that smaller discrete polypeptides are accumulated after 120 minutes of incubation. These polypeptides correspond to growing fibroin chains. This pattern of translation products suggests that elongation might decelerate at specific sites of the fibroin mRNA. These results show that a tRNA pool adjusted to mRNA codon frequency is required to obtain the maximal average elongation rate. A stochastic model based on random acceptance of tRNA at the ribosomal A site for the codon-anticodon recognition process can explain this phenomenon. It can also explain the occurrence of the unfinished discrete fibroin polypeptides during in vitro translation. © 1981 Masson, Paris.SCOPUS: ar.jinfo:eu-repo/semantics/publishe