GALLET , Armel

A major challenge of developmental biology is to understand how cells coordinate developmental behaviors with their neighbors. To achieve this, cells often employ signaling molecules that emanate from a local source and act at a distance on target cells. The Hedgehog morphogen is an essential signaling molecule required for numerous processes...

A major challenge of developmental biology is to understand how cells coordinate developmental behaviors with their neighbors. To achieve this, cells often employ signaling molecules that emanate from a local source and act at a distance on target cells. The Hedgehog morphogen is an essential signaling molecule required for numerous processes...

Les pesticides biologiques ou biopesticides sont de plus en plus utilisés pour lutter contre les nuisibles et les plantes adventices. Parmi ceux-ci figurent les bioinsecticides Btk. Or, une utilisation accrue de ces bioinsecticides pourrait avoir, sur le long terme, des conséquences sur la faune (l'environnement) et la santé publique ...

A major challenge of developmental biology is to understand how cells coordinate developmental behaviors with their neighbors. To achieve this, cells often employ signaling molecules that emanate from a local source and act at a distance on target cells. The Hedgehog morphogen is an essential signaling molecule required for numerous processes...

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Hedgehog (Hh) family members are secreted proteins that can act at short and long range to direct cell fate decisions during developmental processes. In both Drosophila and vertebrates, the morphogenetic gradient of Hh must be tightly regulated for correct patterning. The posttranslational modification of Hh by a cholesterol adduct participates...

Morphogenetic gradient of Hh is tightly regulated for correct patterning in Drosophila and vertebrates. The Patched (Ptc) receptor is required for restricting Hh long-range activity in the imaginal discs. In this study, we investigate the different types of Hh accretion that can be observed in the Drosophila embryonic epithelial cells. We found...

The digestive tract is subjected to many aggressions throughout animal life. Since disruptions of gut physiology impact on animal fitness and survival, maintenance of gut integrity and functionality is essential for the individual. Over the last 40 years, research on rodents has aimed at understanding how cellular homeostasis of the digestive...

The intestine is endowed with an innate immune system that is required to fight any exogenous bacteria that are swallowed along with the food. The first line of defense that is mounted by the gut epithelium is the release of immune Reactive Oxygen Species (ROS), such as hypochlorous acid (HOCl), into the lumen. HOCl is produced within 1.5 h of...

Hedgehog (Hh) and Wingless (Wg) morphogens specify cell fate in a concentration-dependent manner in the Drosophila wing imaginal disc. Proteoglycans, components of the extracellular matrix, are involved in Hh and Wg stability, spreading, and reception. In this study, we demonstrate that the glycosyl-phosphatidyl-inositol (GPI) anchor of the...

[Abstract] The intestine is a central organ required for the digestion of food, the absorption of nutrients and for fighting against aggressors ingested along with the food. Impairment of gut physiology following mucosal damages impacts its digestive capacities that consequently will affect growth, wellbeing or even survival of the individual....

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Plant protection measures are necessary to prevent pests and diseases from attacking and destroying crop plants and to meet consumer demands for agricultural produce. In the last decades the use of chemical pesticides has largely increased. Farmers are looking for alternatives. Biopesticides should be considered a sustainable solution. They may...

Hedgehog family members are secreted proteins involved in numerous patterning mechanisms. Different posttranslational modifications have been shown to modulate Hedgehog biological activity. We investigated the role of these modifications in regulating subcellular localization of Hedgehog in the Drosophila embryonic epithelium. We demonstrate...

When sporulating, Bacillus thuringiensis produces paracrystalline inclusions containing one or more proteins which are mainly responsible for the entomopathogenic properties of this bacterium. Such proteins mostly belong to the Cry family which, after spore lysis and solubilization of the crystals, are delivered to specific zones of the gut....

Most of the detrimental effects of using conventional insecticides to control crop pests are now well identified and are nowadays major arguments for replacing such compounds by the use of biological control agents. In this respect, the bacterium Bacillus thuringiensis var. kurstaki and Trichogramma (Hymenoptera: Trichogrammatidae) parasitic...

Bacillus thuringiensis (Bt), belonging to the Bacillus cereus (Bc) group, is commonly used as a biopesticide worldwide due to its ability to produce insecticidal crystals during sporulation. The use of Bt, especially subspecies aizawai and kurstaki, to control pests such as Lepidoptera, generally involves spraying mixtures containing spores and...

The Hedgehog morphogen is a major developmental regulator that acts at short and long range to direct cell fate decisions in invertebrate and vertebrate tissues. Hedgehog is the only known metazoan protein to possess a covalently linked cholesterol moiety. Although the role of the cholesterol group of Hedgehog remains unclear, it has been...

Bacillus thuringiensis (Bt), belonging to the Bacillus cereus (Bc) group, is commonly used as a biopesticide worldwide, due to its ability to produce insecticidal protein crystals during sporulation. The use of Bt, especially subspecies aizawai and kurstaki, to control pests such as Lepidoptera generally involves spraying mixtures containing...

Cell fate determination during developmental patterning is often controlled by concentration gradients of morphogens. In the epithelial field, morphogens like the Hedgehog (Hh) peptides diffuse both apically and basolaterally; however, whether both pools of Hh are sensed at the cellular level is unclear. Here, we show that interfering with the...

The graded Hedgehog (Hh) signal is transduced by the transmembrane Smoothened (Smo) proteins in both vertebrates and invertebrates. In Drosophila, associations between Smo and the Fused (Fu)/Costal-2 (Cos2)/Cubitus Interruptus (Ci) cytoplasmic complex lead to pathway activation, but it remains unclear how the cytoplasmic complex responds to and...

Commercial Bacillus thuringiensis formulations have non-intentional adverse effects on Drosophila species. German Drosophila Meeting