Bases cellulaires et moléculaires de la discrimination des odeurs à signification biologique chez les insectes

National audienc

Bases cellulaires et moléculaires de la discrimination des odeurs à signification biologique chez les insectes

National audienc

Characterization of putative OBP/PBP in the bee

National audienc

Biochemical purification and molecular cloning of odorant-binding proteins-like of the honeybee Apis mellifera

National audienc

Cyclo-oxygenase 2 tissue distribution and developmental pattern of expression in the chicken

International audience1. Cyclo-oxygenase 2 (COX-2) is implicated in multiple physiopathological processes. We have studied its physiological expression during chicken embryogenesis. 2. An original procedure was set to prepare a COX-2 probe from red blood cells. In situ hybridization, reverse transcription-polymerase chain reaction and northern blots, were performed on chick embryos from embryonic day (E) 3 to postnatal day 15. 3. In the mesonephros, the signal detected in mesonephric tubules presented a slow increase from E5 to E9, a plateau up to E12 and then a decrease, while the signal increased in the metanephros and then decreased after hatching. Transient expression of COX-2 mRNA in endothelial cells of the infundibulum of the aorta was also detected between E12 and E17. 4. This enzyme may have important roles in kidney morphogenesis during early embryonic stages and in tubular functions during development and in adult life. In the cardiovascular system, its vasodilatory effect could modulate the vasoconstrictor effect of the systolic pressure between E12 and E17 and contribute to a normal morphogenesis of the arterial tree and heart

Serine protease inhibitor Spi2 mediated apoptosis of olfactory neurons

The olfactory epithelium of adult mouse, where primary sensory neurons are massively committed to apoptosis by removal of their synaptic target, was used as a model to determine in vivo mechanisms for neuronal cell death induction. A macro-array assay revealed that the death of olfactory neurons is accompanied with over-expression of the serine protease inhibitor Spi2. This over-expression is associated with decreased serine protease activity in the olfactory mucosa. Moreover, in vitro or in vivo inhibition of serine proteases induced apoptotic death of olfactory neuronal cells. Interestingly, Spi2 over-expression is not occurring in olfactory neurons but in cells of the lamina propria, suggesting that Spi2 may act extracellularly as a cell death inducer. In that sense, we present evidence that in vitro Spi2 overexpression generates a secreted signal for olfactory neuron death. Hence, taken together these results document a possible novel mechanism for apoptosis induction that might occur in response to neurodegenerative insults

Optimization of the production of a honeybee odorant-binding protein by Pichia pastoris

Optimization of the production of a honeybee odorant-binding protein by [i]Pichia pastoris[/i

Separation, characterization and sexual heterogeneity of multiple putative odorant-binding proteins in the honeybee Apis mellifera L. (Hymenoptera: Apidea).

2 tables 5 graph.International audienceAccording to precise molar mass determined by mass spectrometry and N-terminal sequence, some 25 odorant-binding-like proteins were characterized from the antennae and legs of worker and drone honeybees. Antennal specific proteins, composed of six different molecules, were classified into three subclasses according to N-terminal sequence homology. The major sexual difference was shown to lie in the relative abundance of these antennal specific proteins and in the occurrence of a drone-specific isoform. At least 19 other related proteins were found to occur in antennae and legs, forming another class showing homology with insect OBP. Genotype comparison of two honeybee races revealed a variability limited to this second class. Provided that these odorant-binding-like proteins are indeed able to bind odorants or pheromones, the question of whether their peculiar multiplicity contributes to the remarkable capacity of the honeybee to discriminate among a wide range of odor molecules is raised

Identification and developmental profiles of hexamerins in antenna and hemolymph of the honeybee, Apis mellifera.

55 ref. 6 graph.International audienceFour distinct hexamerin subunits (referred to as "hexamerins" in the following text) have been identified in the developing honeybee, Apis mellifera, by N-terminal protein sequencing. Hexamerins are abundant in the hemolymph of late larval and early pupal stages, and gradually decline during metamorphosis and adult development. Three hexamerins in the 70 kDa range have been found (Hex70a, Hex70b, Hex70c). In worker and drone, Hex70a is the only hexamerin present in large amount in later adult stages. Hex70b and c exhibit a similar developmental profile, disappearing in the drone just before adult emergence, and in the worker just after. Hex70b or Hex70c are still detectable in the adult queen. Hex80/110 likely exist in at least 3 different subunits, 1 of 110 kDa, and 2 of around 80 kDa, which all share a common N-terminus. They disappear during metamorphosis earlier than Hex70b and c. All these hexamerins have been found also in the antenna, suggesting their utilization in building up of antennal cuticle structures

Two novel members of OBP family identified in the honeybee : sexual dimorphism and development studies

International audienc