A carboxylesterase, Esterase-6, modulates sensory physiological and behavioral response dynamics to pheromone in Drosophila

Conclusions: Our study presents evidence that Est-6 plays a role in the physiological and behavioral dynamics of sex pheromone response in Drosophila males and supports a role of Est-6 as an odorant-degrading enzyme (ODE) in male antennae. Our results also expand the role of Est-6 in Drosophila biology, from reproduction to olfaction, and highlight the role of ODEs in insect olfaction

Association entre les affections buccodentaires et le cancer colorectal : une revue et synthèse de la littérature

Position du problème: La parodontite chronique et l’édentement sont des affections buccodentaires chroniques qui, depuis quelques décennies, sont incriminées dans la survenue de différents types de cancers. Cette revue de littérature avait pour but d’examiner l’association entre le cancer colorectal et ces affections buccodentaires. Résultats: Les études épidémiologiques évaluant une association potentielle entre la parodontite, l’édentement et le cancer colorectal sont peu nombreuses. Cependant, plusieurs mécanismes plaident en faveur de cette association, notamment l’inflammation, la nutrition et possiblement l’infection par certains pathogènes, comme le suggère cette revue de la littérature.Background: Chronic periodontitis and tooth loss are chronic oral conditions that, in recent decades, have been implicated in the occurence of certain types of cancer. In this review, we address the question of whether colorectal cancer is associated with these oral conditions. Results: Epidemiological studies evaluating a potential association between periodontitis, tooth loss and colorectal cancer are scarce. However, several mechanisms argue in favor of this association, notably inflammation, nutrition and possibly infection by specific bacteria, as suggested by this literature review

Imaging Ca²+ dynamics in cone photoreceptor axon terminals of the mouse retina

Retinal cone photoreceptors (cones) serve daylight vision and are the basis of color discrimination. They are subject to degeneration, often leading to blindness in many retinal diseases. Calcium (Ca2+), a key second messenger in photoreceptor signaling and metabolism, has been proposed to be indirectly linked with photoreceptor degeneration in various animal models. Systematically studying these aspects of cone physiology and pathophysiology has been hampered by the difficulties of electrically recording from these small cells, in particular in the mouse where the retina is dominated by rod photoreceptors. To circumvent this issue, we established a two-photon Ca2+ imaging protocol using a transgenic mouse line that expresses the genetically encoded Ca²+ biosensor TN-XL exclusively in cones and can be crossbred with mouse models for photoreceptor degeneration. The protocol described here involves preparing vertical sections (“slices”) of retinas from mice and optical imaging of light stimulus-evoked changes in cone Ca²+ level. The protocol also allows “in-slice measurement” of absolute Ca²+ concentrations; as the recordings can be followed by calibration. This protocol enables studies into functional cone properties and is expected to contribute to the understanding of cone Ca²+ signaling as well as the potential involvement of Ca²+ in photoreceptor death and retinal degeneration

Theoretical study of optical properties of anti phase domains in GaP

International audienceIII-V/Si heterostructures are currently investigated for silicon photonics and solar energy conversion. In particular, dilute nitride alloy GaAsPN grown on a GaP/Si platform exhibits lattice match with Si and an optimal band gap configuration for tandem solar cell devices. However, monolithic "coherent" growth of the GaP thin layer on Si suffers from the nucleation of extended structural defects, which can hamper device operation as well as the GaP/Si interface level and through their propagation inside the overall heterostructure. However, the effect of such structural defects on optical and transport properties is actually not well understood in details. In this letter, we investigate the anti phase domains defect (also called inversion domains) by means of ab initio calculations giving insights into the alteration of optical and transport properties of GaP due to the defective GaP/Si interface

Emergence as cornerstone in understanding evolution : examples from zoology

Peer reviewedScience is the way in which humankind explore and understand the physical universe. The biological sciences and especially the zoological sciences provide us with an understanding of ourselves – how we function, how we evolved and how we relate to the rest of nature. During our first tentative steps on the road of rational thought biology played a pivotal role in unlocking the nature of humankind, opened our eyes to natural processes and laid the foundation for the scientific method of inquiry. Over the past three millennia the biological sciences evolved into many subjects including medicine, anatomy, comparative morphology, embryology, palaeontology, genetics, biochemistry and physiology. Although biologists are interested in every aspect of life, it is primarily through the study of humans and human interests that we gained access to the natural world. Genetics grew from our interest in promoting agriculture and animal husbandry and the study of genetic deviations in humans. The study of human evolution dominates palaeontology. The study of embryology, comparative morphology and anatomy began with and is still dominated by the study of humans. Human needs dominate the endeavours in the fields of biochemistry, physiology and medicine.Research Institute for Theology and Religio

Ca(v)1.4 L-Type Calcium Channels Contribute to Calpain Activation in Degenerating Photoreceptors of rd1 Mice

Retinitis pigmentosa is an inherited blinding disorder characterized by progressive degeneration and loss of photoreceptors. The exact mechanism of degeneration and cell death of photoreceptors is not known, but is thought to involve disturbed Ca2+-signaling. Ca2+ can enter the photoreceptor cell via outer segment cyclic nucleotide-gated (CNG) channels or synaptic Ca(v)1.4 L-type voltage-gated calcium channels (VGCC). Previously, we have shown that genetic ablation of the Cngb1 gene encoding the B subunit of the rod CNG channel delays the fast progressing degeneration in the rd1 mutant mouse model of retinitis pigmentosa. In this study, we crossbred rd1 mice with the Cacna1f-deficient mouse lacking the Ca(v)1.4 alpha 1 subunit of the L-type VGCC. Longitudinal in vivo examinations of photoreceptor layer thickness by optical coherence tomography revealed a significant, but not sustained delay of retinal degeneration in Cacna1f x rd1 double mutant mice compared to rd1 mice. This was accompanied by a reduction of TUNEL positive cells in the early phase of rod degeneration. Remarkably, Cacna1f x rd1 double mutant mice displayed a strong decrease in the activation of the Ca2+-dependent protease calpain during photoreceptor loss. Our results show that genetic deletion of the synaptic Ca-v 1.4 L-type VGCCs impairs calpain activation and leads to a short-term preservation of photoreceptors in the rd1 mouse