Imaging pheromone sensing in a mouse vomeronasal acute tissue slice preparation.

Peter Karlson and Martin Lüscher used the term pheromone for the first time in 1959 to describe chemicals used for intra-species communication. Pheromones are volatile or non-volatile short-lived molecules secreted and/or contained in biological fluids, such as urine, a liquid known to be a main source of pheromones. Pheromonal communication is implicated in a variety of key animal modalities such as kin interactions, hierarchical organisations and sexual interactions and are consequently directly correlated with the survival of a given species. In mice, the ability to detect pheromones is principally mediated by the vomeronasal organ (VNO), a paired structure located at the base of the nasal cavity, and enclosed in a cartilaginous capsule. Each VNO has a tubular shape with a lumen allowing the contact with the external chemical world. The sensory neuroepithelium is principally composed of vomeronasal bipolar sensory neurons (VSNs). Each VSN extends a single dendrite to the lumen ending in a large dendritic knob bearing up to 100 microvilli implicated in chemical detection. Numerous subpopulations of VSNs are present. They are differentiated by the chemoreceptor they express and thus possibly by the ligand(s) they recognize. Two main vomeronasal receptor families, V1Rs and V2Rs, are composed respectively by 240 and 120 members and are expressed in separate layers of the neuroepithelium. Olfactory receptors (ORs) and formyl peptide receptors (FPRs) are also expressed in VSNs. Whether or not these neuronal subpopulations use the same downstream signalling pathway for sensing pheromones is unknown. Despite a major role played by a calcium-permeable channel (TRPC2) present in the microvilli of mature neurons TRPC2 independent transduction channels have been suggested. Due to the high number of neuronal subpopulations and the peculiar morphology of the organ, pharmacological and physiological investigations of the signalling elements present in the VNO are complex. Here, we present an acute tissue slice preparation of the mouse VNO for performing calcium imaging investigations. This physiological approach allows observations, in the natural environment of a living tissue, of general or individual subpopulations of VSNs previously loaded with Fura-2AM, a calcium dye. This method is also convenient for studying any GFP-tagged pheromone receptor and is adaptable for the use of other fluorescent calcium probes. As an example, we use here a VG mouse line, in which the translation of the pheromone V1rb2 receptor is linked to the expression of GFP by a polycistronic strategy

Morphological and physiological species-dependent characteristics of the rodent Grueneberg ganglion.

In the mouse, the Grueneberg ganglion (GG) is an olfactory subsystem implicated both in chemo- and thermo-sensing. It is specifically involved in the recognition of volatile danger cues such as alarm pheromones and structurally-related predator scents. No evidence for these GG sensory functions has been reported yet in other rodent species. In this study, we used a combination of histological and physiological techniques to verify the presence of a GG and investigate its function in the rat, hamster, and gerbil comparing with the mouse. By scanning electron microscopy (SEM) and transmitted electron microscopy (TEM), we found isolated or groups of large GG cells of different shapes that in spite of their gross anatomical similarities, display important structural differences between species. We performed a comparative and morphological study focusing on the conserved olfactory features of these cells. We found fine ciliary processes, mostly wrapped in ensheating glial cells, in variable number of clusters deeply invaginated in the neuronal soma. Interestingly, the glial wrapping, the amount of microtubules and their distribution in the ciliary processes were different between rodents. Using immunohistochemistry, we were able to detect the expression of known GG proteins, such as the membrane guanylyl cyclase G and the cyclic nucleotide-gated channel A3. Both the expression and the subcellular localization of these signaling proteins were found to be species-dependent. Calcium imaging experiments on acute tissue slice preparations from rodent GG demonstrated that the chemo- and thermo-evoked neuronal responses were different between species. Thus, GG neurons from mice and rats displayed both chemo- and thermo-sensing, while hamsters and gerbils showed profound differences in their sensitivities. We suggest that the integrative comparison between the structural morphologies, the sensory properties, and the ethological contexts supports species-dependent GG features prompted by the environmental pressure

Possibilités d'amélioration des conditions de vêlage par sélection. I. – Technique de mesure de l'ouverture pelvienne des bovins

International audienc

The Crc global regulator binds to an unpaired A-rich motif at the Pseudomonas putida alkS mRNA coding sequence and inhibits translation initiation

Crc is a key global translational regulator in Pseudomonads that orchestrates the hierarchy of induction of several catabolic pathways for amino acids, sugars, hydrocarbons or aromatic compounds. In the presence of amino acids, which are preferred carbon sources, Crc inhibits translation of the Pseudomonas putida alkS and benR mRNAs, which code for transcriptional regulators of genes required to assimilate alkanes (hydrocarbons) and benzoate (an aromatic compound), respectively. Crc binds to the 5′-end of these mRNAs, but the sequence and/or structure recognized, and the way in which it inhibits translation, were unknown. We have determined the secondary structure of the alkS mRNA 5′-end through its sensitivity to several ribonucleases and chemical reagents. Footprinting and band-shift assays using variant alkS mRNAs have shown that Crc specifically binds to a short unpaired A-rich sequence located adjacent to the alkS AUG start codon. This interaction is stable enough to prevent formation of the translational initiation complex. A similar Crc-binding site was localized at benR mRNA, upstream of the Shine–Dalgarno sequence. This allowed predicting binding sites at other Crc-regulated genes, deriving a consensus sequence that will help to validate new Crc targets and to discriminate between direct and indirect effects of this regulator

New insight about the functionality of oenological tannins; Main results of the working group on oenological tannins

This communication synthetize all the results obtained by the OIV working group on oenological tannins to the current date. The obtained results confirm that oenological tannins really exert a protection effect against grape juice and wine oxidation because they have antioxidant activity, they consume directly oxygen and they exert an inhibitory effect on the laccase activity. Moreover, oenological tannins also exert a copigmentation effect which can improve and protect de color of red wines

The art of video MashUp: supporting creative users with an innovative and smart application

In this paper, we describe the development of a new and innovative tool of video mashup. This application is an easy to use tool of video editing integrated in a cross-media platform; it works taking the information from a repository of videos and puts into action a process of semi-automatic editing supporting users in the production of video mashup. Doing so it gives vent to their creative side without them being forced to learn how to use a complicated and unlikely new technology. The users will be further helped in building their own editing by the intelligent system working behind the tool: it combines semantic annotation (tags and comments by users), low level features (gradient of color, texture and movements) and high level features (general data distinguishing a movie: actors, director, year of production, etc.) to furnish a pre-elaborated editing users can modify in a very simple way

Dihaploid Coffea arabica genome sequencing and assembly.

Coffea arabica which accounts for 70% of world coffee production is an allotetraploid with a genome size of approximately 1.3 Gb and is derived from the hybridization of C. canephora (710 Mb) and C. eugenioides (670 Mb). To elucidate the evolutionary history of C. arabica, and generate critical information for breeding programs, a sequencing project is underway to finalize a reference genome using a dihaploid line and a set of Menu Abstract: Dihaploid Coffea arabica Genome Sequencing and Assembly (Plant and Animal Genome XXIII Conference) https://pag.confex.com/pag/xxiii/webprogram/Paper16983.html [25/02/2015 15:00:12] 30 C. arabica accessions