Project description:gd T cells have an important yet incompletely defined role in inflammation associated with a variety of infectious and autoimmune conditions. To better understand the precise roles of gd T cells relative to ab T cells in a specific infection, we utilized Salmonella Enterica Serovar Typhimurium (S. typhimurium) infection in cattle as it is a leading cause of disease in cattle and closely approximates S. typhimurium-induced enterocolitis in humans. To best represent phenotype and gene expression changes occurring in the gut mucosa early in S. typhimurium infection, gd and ab T cells were collected directly from the mesenteric lymphatic ducts and analyzed by FACS or immediately sorted and processed for microarray analysis. Gene expression profiles were compared at intervals during infection within T cell subsets. The majority of gene expression changes in both subsets occurred 48 hours after infection. In response to S. typhimurium infection there was an increase in expression of several genes in gd T cells which were indicative of activation, proliferation and innate function, whereas in ab T cells gene expression changes suggested a lack of S. typhimurium-specific response. This work represents the first focus on gene expression trends in tissue-derived T lymphocytes in an in vivo model that is highly relevant to human S. typhimurium-induced enterocolitis. Experiment Overall Design: For one mock infection (calf 156) and two experimental S. typhimurium infections (calves 112 and 162), gd and ab lymphatic T cells were stained with GD3.8 directly conjugated to FITC, washed, and sorted on a Vantage SE cell sorter (BD Immunocytometry Systems) as previously described. Sorted gd and ab T cells were collected directly into TRIzol reagent (Invitrogen; calf 112) and lysed or suspended in Buffer RLT (Qiagen; calves 156 and 162) and lysed using Qiashredder columns, then frozen at -80oC. RNA was extracted following the manufacturerâs protocol for Trizol (Invitrogen) extraction, or RNeasy (Qiagen) column purification, assessed on a Bioanalyzer 2100 (Agilent Technologies), and amplified either using Affymetrix Two-cycle (calf 112) target labeling protocol with 100 ng total RNA or the One-cycle protocol (calves 156 and 162) with approximately 1.6 micrograms of total RNA as described in the GeneChip® Expression Analysis Technical Manual (June 2004). Hybridizations to Genechip® Bovine Genome Arrays (Affymetrix) were performed with 15 micrograms biotin labeled cRNA. Washing and staining was performed in the GeneChip® Fluidics Station 450 using the Midi_euk2v3 protocol. Chip scans were performed on the Affymetrix GeneChip® Scanner 3000. GeneChip® Operating Software (GCOS v.1.1, Affymetrix) was used for data collection. Experiment Overall Design: Table I represents annotated genes of potential interest that changed 2 fold or greater in expression between 0 and 48 hours post-Salmonella infection (calves 112 and 162) or mock-infection (calf 156) in T cell subsets.
Project description:The Toll-like receptor (TLR) and peptidoglycan recognition protein 1 (PGLYRP1) genes play key roles in the innate immune systems of mammals. While the TLRs recognize a variety of invading pathogens and induce innate immune responses, PGLYRP1 is directly microbicidal. We used custom allele-specific assays to genotype and validate 220 diallelic variants, including 54 nonsynonymous SNPs in 11 bovine innate immune genes (TLR1-TLR10, PGLYRP1) for 37 cattle breeds. Bayesian haplotype reconstructions and median joining networks revealed haplotype sharing between Bos taurus taurus and Bos taurus indicus breeds at every locus, and we were unable to differentiate between the specialized B. t. taurus beef and dairy breeds, despite an average polymorphism density of one locus per 219 bp. Ninety-nine tagSNPs and one tag insertion-deletion polymorphism were sufficient to predict 100% of the variation at all 11 innate immune loci in both subspecies and their hybrids, whereas 58 tagSNPs captured 100% of the variation at 172 loci in B. t. taurus. PolyPhen and SIFT analyses of nonsynonymous SNPs encoding amino acid replacements indicated that the majority of these substitutions were benign, but up to 31% were expected to potentially impact protein function. Several diversity-based tests provided support for strong purifying selection acting on TLR10 in B. t. taurus cattle. These results will broadly impact efforts related to bovine translational genomics.
Project description:BackgroundWe present here the assembly of the bovine genome. The assembly method combines the BAC plus WGS local assembly used for the rat and sea urchin with the whole genome shotgun (WGS) only assembly used for many other animal genomes including the rhesus macaque.ResultsThe assembly process consisted of multiple phases: First, BACs were assembled with BAC generated sequence, then subsequently in combination with the individual overlapping WGS reads. Different assembly parameters were tested to separately optimize the performance for each BAC assembly of the BAC and WGS reads. In parallel, a second assembly was produced using only the WGS sequences and a global whole genome assembly method. The two assemblies were combined to create a more complete genome representation that retained the high quality BAC-based local assembly information, but with gaps between BACs filled in with the WGS-only assembly. Finally, the entire assembly was placed on chromosomes using the available map information.Over 90% of the assembly is now placed on chromosomes. The estimated genome size is 2.87 Gb which represents a high degree of completeness, with 95% of the available EST sequences found in assembled contigs. The quality of the assembly was evaluated by comparison to 73 finished BACs, where the draft assembly covers between 92.5 and 100% (average 98.5%) of the finished BACs. The assembly contigs and scaffolds align linearly to the finished BACs, suggesting that misassemblies are rare. Genotyping and genetic mapping of 17,482 SNPs revealed that more than 99.2% were correctly positioned within the Btau_4.0 assembly, confirming the accuracy of the assembly.ConclusionThe biological analysis of this bovine genome assembly is being published, and the sequence data is available to support future bovine research.
Project description:Bene expression profile of Angus bovine testis tissue at 2, 4 and 8 weeks of age using Affymetrix Bovine GeneChip Experiment Overall Design: Samples obtained from Angus bull calves at 2, 4 and 8 weeks of age. Two replicates at each age, 6 total samples.