The semaphorins are a large group of cell surface and secreted proteins implicated in axonal pathfinding. Here we show that the secreted mouse semaphorin D (SemD) is synthesized as an inactive precursor (proSemD) and becomes repulsive for sensory and sympathetic neurites upon proteolytic cleavage. ProSemD processing can be blocked completely by an inhibitor selective for furin-like endoprotease...

Over the last three decades a large body of research in the field of ELECTRE family methods appeared. This research has been conducted by several researchers mainly in Europe. The purpose of this chapter is to present a survey of the ELECTRE methods since their first appearance in mid-sixties, when ELECTRE I was proposed by Bernard Roy and his colleagues at SEMA consultancy company. The chapter...

Attractive and repulsive molecules such as Semaphorins (Sema) trigger rapid responses that control the navigation of axonal growth cones. The role of vesicular traffic in axonal guidance is still largely unknown. The exocytic vesicular soluble N-ethylmaleimide sensitive fusion protein attachment protein receptor (SNARE) Synaptobrevin 2 (Syb2) is known for mediating neurotransmitter release in m...

The spatiotemporal integration of adhesion and signaling during neuritogenesis is an important prerequisite for the establishment of neuronal networks in the developing brain. In this study, we describe the role of the L1-type CAM Neuroglian protein (NRG) in different steps of Drosophila mushroom body (MB) neuron axonogenesis. Selective axon bundling in the peduncle requires both the extracellu...

Sensory axons extend from the chick olfactory epithelium to the telencephalon well before the maturation of their target, the olfactory bulb. During a waiting period of several days, olfactory axons arrive and accumulate outside the CNS while the bulb differentiates beneath them. Semephorin-3A is expressed in the tel-encephalon during this period and has been proposed to prevent their entry int...

Entre le dernier tiers du XIX et le premier du XX siècle, Léopold Piguet, horloger et botaniste amateur de la Vallée de Joux, trouvant la flore du Jura un peu pauvre, s’est mis en tête de l’enrichir. Il créa d’abord, autour de sa maison, un petit jardin botanique où il multiplia des espèces alpines ou étrangères, qu’il sema ensuite dans divers sites de la Vallée, au Mont Tendre en particulier. ...

In Drosophila, plexin A is a functional receptor for semaphorin-1a. Here we show that the human plexin gene family comprises at least nine members in four subfamilies. Plexin-B1 is a receptor for the transmembrane semaphorin Sema4D (CD100), and plexin-C1 is a receptor for the GPI-anchored semaphorin Sema7A (Sema-K1). Secreted (class 3) semaphorins do not bind directly to plexins, but rather ple...