Relationship between sperm quality traits and field-fertility of porcine semen

An investigation involving seven boars, active in artificial insemination, and 1,350 multiparous sows was conducted at a private farm and aimed at examining the relationship between sperm quality traits and boar fertility in terms of farrowing rate and litter size. This experiment was done for 6 months. The semen samples were evaluated for subjective sperm motility and concentration. Ejaculates with at least 1 × 108 sperm/mL and 70% sperm progressive motility were extended with a commercial medium to 30 × 106 sperm/mL and used for artificial insemination (AI). AI dose was 100 mL semen containing 3 × 109 spermatozoa. Aliquots of diluted semen were assessed for live morphologically normal spermatozoa (LMNS, eosin-nigrosin stain exclusion assay) and sperm chromatin instability (SCI, acridine orange assay). Farrowing rates according to different boar sperm varied (p < 0.001) from 59.3 to 88.92%. The mean values of LMNS (47.2~76.5%) and SCI (0.16~4.67%) differed significantly among boars. LMNS (r = 0.79, p < 0.05) and SCI (r = -0.90, p < 0.02) accounted for 62.2 and 81.7% of the variability in farrowing rates, respectively. After the combination of sperm traits, the relationship between percentage of LMNS with stable chromatin structure and farrowing rate was significant (r = 0.86, p < 0.05). The number of live piglets per parturition was not significantly correlated with sperm quality attributes. In conclusion, boar fertility after AI with freshly diluted semen can be predicted based on the evaluation of sperm morphology and chromatin integrity

Chemotactic response and adaptation dynamics in Escherichia coli

Adaptation of the chemotaxis sensory pathway of the bacterium Escherichia coli is integral for detecting chemicals over a wide range of background concentrations, ultimately allowing cells to swim towards sources of attractant and away from repellents. Its biochemical mechanism based on methylation and demethylation of chemoreceptors has long been known. Despite the importance of adaptation for cell memory and behavior, the dynamics of adaptation are difficult to reconcile with current models of precise adaptation. Here, we follow time courses of signaling in response to concentration step changes of attractant using in vivo fluorescence resonance energy transfer measurements. Specifically, we use a condensed representation of adaptation time courses for efficient evaluation of different adaptation models. To quantitatively explain the data, we finally develop a dynamic model for signaling and adaptation based on the attractant flow in the experiment, signaling by cooperative receptor complexes, and multiple layers of feedback regulation for adaptation. We experimentally confirm the predicted effects of changing the enzyme-expression level and bypassing the negative feedback for demethylation. Our data analysis suggests significant imprecision in adaptation for large additions. Furthermore, our model predicts highly regulated, ultrafast adaptation in response to removal of attractant, which may be useful for fast reorientation of the cell and noise reduction in adaptation.Comment: accepted for publication in PLoS Computational Biology; manuscript (19 pages, 5 figures) and supplementary information; added additional clarification on alternative adaptation models in supplementary informatio

Apoptosis of CD4+CD25high T Cells in Type 1 Diabetes May Be Partially Mediated by IL-2 Deprivation

from T1D subjects. in T1D may be caught up in a relatively deficient cytokine milieu. function in subjects predisposed to T1D

POTENTIALITES DE PRODUCTION ET DE CONSOMMATION DE LA VIANDE CUNICOLE AU LIBAN

[EN] In order to know the situation of rabbit production and consumption in Lebanon, a survey was conducted concerning ali the producers (23), 137 traders, 48 restaurants and 5500 consumers covering all the regions and essentially the Lebanese religions. Results has revealed a traditional rearing methods with 17 tons of live weight of production per year. Only 14.5% of supermarkets and 4% of restaurants are selling rabbit. However, 85% of the supermarkets and 74% of the restaurants which do not sell the rabbit are for introducing this kind of meat in their sales point in case an advertising campaign is realised- Moreover, the rabbit eater percentage (32.41%) are divided into appreciators (80%) and non appreciators (20%) and 46% of the non consumers accept to taste rabbit meat at the time of its availability in the Lebanese market. Also, Christians are the most opened for consuming rabbit (38%), followed the sunnites and druzes (23.2% and 25.8% respectively) and only 5.5% of chiites (P<0.05).[FR] Afin de connaitre la situation de la production et de la consommation de la viande cunicole au Uban, une enquete a été réalisée aupres de tous les producteurs (23), de 137 commer~nts, 48 restaurants et de 5500 consommateurs couvrant toutes les régions et essentiellement les religions libanaises. Les résultats ont montré que l'élevage est essentiellement traditionnel et que la production annuelle ne dépasse pas 17 tonnes de poids vif. 14.5% des supermarchés et 74% des restaurants sont prets a introduire le lapin dans leur point de vente au cas ou une campagne publicitaire est assumée. 32% de notre population a déja goüté la viande du lapin dont 80% ont apprécié le goót; 46% des non consommateurs acceptent de goóter si la viande est disponible sur le marché. 38% des chrétiens, 25.8% des sunnites et 23.2% des druzes ont déja consommé du lapin contre 5.5% seulement chez les chutes -P<0.05). La consultation d'un religieux chiite nous a confirmés /'existence d'un interdit religieux figurant, non dans le Coran mais dans le "Hadith" ou "discussions avec le prophBte".Chalah, T.; Hajj, E. (1996). POTENTIALITES DE PRODUCTION ET DE CONSOMMATION DE LA VIANDE CUNICOLE AU LIBAN. World Rabbit Science. doi:10.4995/wrs.1996.273SWORD04

Fatty acid composition, glutathione peroxidase and superoxide dismutase activity and total antioxidant activity of avian semen

This work demonstrates that spermatozoa from five avian species (chicken, turkey, guinea fowl, duck and goose) are all characterised by high proportions of polyunsaturated fatty acids, from 46 (turkey) to 55% (duck) of total. For each of the species, the most abundant fatty acids were arachidonic (20:4n-6) and docosatetraenoic (22:4n-6) acids, representing between 22 (turkey) and 40% (chicken) of total. Significant activities of the major isozymes of superoxide dismutase and glutathione peroxidase, which protect against the peroxidation associated with high degree of fatty acid unsaturation, were found in spermatozoa from all species. The seminal plasma also had these activities and showed additional mechanisms for protecting spermatozoa from peroxidation. In general terms, these lipid and enzyme proteins were similar between the five avian species and different from those reported for mammalian sperm. Copyright (C) 1998 Elsevier Science Inc

Fatty acid composition, glutathione peroxidase and superoxide dismutase activity and total antioxidant activity of avian

Abstract This work demonstrates that spermatozoa from five avian species (chicken, turkey, guinea fowl, duck and goose) are all characterised by high proportions of polyunsaturated fatty acids, from 46 (turkey) to 55% (duck) of total. For each of the species, the most abundant fatty acids were arachidonic (20:4n-6) and docosatetraenoic (22:4n -6) acids, representing between 22 (turkey) and 40% (chicken) of total. Significant activities of the major isozymes of superoxide dismutase and glutathione peroxidase, which protect against the peroxidation associated with high degree of fatty acid unsaturation, were found in spermatozoa from all species. The seminal plasma also had these activities and showed additional mechanisms for protecting spermatozoa from peroxidation. In general terms, these lipid and enzyme proteins were similar between the five avian species and different from those reported for mammalian sperm

Receptor density balances signal stimulation and attenuation in membrane-assembled complexes of bacterial chemotaxis signaling proteins

All cells possess transmembrane signaling systems that function in the environment of the lipid bilayer. In the Escherichia coli chemotaxis pathway, the binding of attractants to a two-dimensional array of receptors and signaling proteins simultaneously inhibits an associated kinase and stimulates receptor methylation—a slower process that restores kinase activity. These two opposing effects lead to robust adaptation toward stimuli through a physical mechanism that is not understood. Here, we provide evidence of a counterbalancing influence exerted by receptor density on kinase stimulation and receptor methylation. Receptor signaling complexes were reconstituted over a range of defined surface concentrations by using a template-directed assembly method, and the kinase and receptor methylation activities were measured. Kinase activity and methylation rates were both found to vary significantly with surface concentration—yet in opposite ways: samples prepared at high surface densities stimulated kinase activity more effectively than low-density samples, whereas lower surface densities produced greater methylation rates than higher densities. FRET experiments demonstrated that the cooperative change in kinase activity coincided with a change in the arrangement of the membrane-associated receptor domains. The counterbalancing influence of density on receptor methylation and kinase stimulation leads naturally to a model for signal regulation that is compatible with the known logic of the E. coli pathway. Density-dependent mechanisms are likely to be general and may operate when two or more membrane-related processes are influenced differently by the two-dimensional concentration of pathway elements