Annotation and classification of the bovine T cell receptor delta genes

Abstract Background: gδ T cells differ from ab T cells with regard to the types of antigen with which their T cell receptors interact; gδ T cell antigens are not necessarily peptides nor are they presented on MHC. Cattle are considered a “gδ T cell high” species indicating they have an increased proportion of gδ T cells in circulation relative to that in “gδ T cell low” species such as humans and mice. Prior to the onset of the studies described here, there was limited information regarding the genes that code for the T cell receptor delta chains of this gδ T cell high species. Results: By annotating the bovine (Bos taurus) genome Btau_3.1 assembly the presence of 56 distinct T cell receptor delta (TRD) variable (V) genes were found, 52 of which belong to the TRDV1 subgroup and were comingled with the T cell receptor alpha variable (TRAV) genes. In addition, two genes belonging to the TRDV2 subgroup and single TRDV3 and TRDV4 genes were found. We confirmed the presence of five diversity (D) genes, three junctional (J) genes and a single constant (C) gene and describe the organization of the TRD locus. The TRDV4 gene is found downstream of the C gene and in an inverted orientation of transcription, consistent with its orthologs in humans and mice. cDNA evidence was assessed to validate expression of the variable genes and showed that one to five D genes could be incorporated into a single transcript. Finally, we grouped the bovine and ovine TRDV1 genes into sets based on their relatedness. Conclusions: The bovine genome contains a large and diverse repertoire of TRD genes when compared to the genomes of “gδ T cell low” species. This suggests that in cattle gδ T cells play a more important role in immune function since they would be predicted to bind a greater variety of antigens

Optical vs. infrared studies of dusty galaxies and AGN: (I) Nebular emission lines

Optical nebular emission lines are commonly used to estimate the star formation rate of galaxies and the black hole accretion rate of their central active nucleus. The accuracy of the conversion from line strengths to physical properties depends upon the accuracy to which the lines can be corrected for dust attenuation. For studies of single galaxies with normal amounts of dust, most dust corrections result in the same derived properties within the errors. However, for statistical studies of populations of galaxies, or for studies of galaxies with higher dust contents such as might be found in some classes of "transition" galaxies, significant uncertainty arises from the dust attenuation correction. We compare the strength of the predominantly unobscured mid-IR [NeII]15.5um + [NeIII]12.8um emission lines to the optical H alpha emission lines in four samples of galaxies: (i) ordinary star forming galaxies, (ii) optically selected dusty galaxies, (iii) ULIRGs, (iv) Seyfert 2 galaxies. We show that a single dust attenuation curve applied to all samples can correct H alpha emission for dust attenuation to a factor better than 2. Similarly, we compare mid-IR [OIV] and optical [OIII] luminosities to find that [OIII] can be corrected to a factor better than 3. This shows that the total dust attenuation suffered by the AGN narrow line region is not significantly different to that suffered by the starforming HII regions in the galaxy. We provide explicit dust attenuation corrections, together with errors, for [OII], [OIII] and H alpha. The best-fit average attenuation curve is slightly greyer than the Milky-Way extinction law, indicating either that external galaxies have slightly different typical dust properties to the Milky Way, or that there is a significant contribution from scattering. Finally, we uncover an intriguing correlation between Silicate absorption and Balmer decrement.Comment: 19 pages, 9 figures, accepted for publication in MNRA

Influence of a blend of fructo-oligosaccharides and sugar beet fiber on nutrient digestibility and plasma metabolites concentrations in healthy Beagles

Objective-To evaluate effects of a blend of fructo-oligosaccharides and sugar beet fiber (4:1) at 3 incorporation rates on nutrient digestibility and plasma glucose, insulin, alpha-aminonitrogen, urea, cholesterol, and triglycerides concentrations measured weekly in nonfed dogs and during a 360-minute period after a meal. Animals-8 castrated 1 to 1.4-year-old young adult male Beagles weighing 10.0 to 13.5 kg. Procedure-Diets containing 2 incorporation rates of a blend of fructo-oligosaccharides and sugar beet fiber (5 and 10% on a dry matter basis [diets B and C, respectively]) were compared with a control diet without additional fiber (diet A). The 3 diets were evaluated for ability to modify digestibility of dry and organic matter, protein, fat, and ash and for effects on plasma glucose, insulin, alpha-aminonitrogen, urea, cholesterol, and triglycerides concentrations. Each diet was fed for 6 weeks; plasma samples were collected weekly before feeding and after feeding on the last day of the period, During 1 week at the end of the 6-week period, dogs were kept in metabolic cages. Each period of the block was followed by a 4-week washout period. Results-Incorporating the blend of fructo-oiigosaccharides and sugar beet fiber in the diet was associated with greater passage of wet feces (diets B and C) and lower protein digestibility (diet C). Postprandial glucose (diet C), urea (diets B and C) and triglyceride (diets B and C) concentrations were significantly (P < 0.01) decreased. Weekly preprandial measurements were characterized by decreased urea (diets B and C), cholesterol (diet C), and triglycerides (diets B and C) concentrations (P < 0.001). Conclusion-Chronic consumption of fermentable fiber is associated with mildly decreased protein digestibility and with metabolic effects in nonfed or fed dogs. Clinical Relevance-A blend of fructo-oligosaccharides and sugar beet fiber should he tested as a dietary aid for treatment of chronic diseases, such as diabetes mellitus or hyperlipidemia, in dogs

Twenty four hours fermentation patterns on diets differing in carbohydrate composition

peer reviewe

Comparison between 4 processing techniques of maize in dogs's diet: Effects on digestibility and on plasma metabolites

peer reviewe

Effects of starch, saccharose and fat in dog's diet on plasma metabolites

peer reviewe