Project description:Digital dermatitis is a painful foot disease compromising welfare in dairy cattle. The disease has a complex multibacterial aetiology, but little is known about its pathogenesis. In this study, gene expression in skin biopsies from five bovine digital dermatitis lesions and five healthy bovine feet was compared using RNA-Seq technology. Differential gene expression was determined after mapping transcripts to the Btau 4.0 genome. Pathway analysis identified gene networks involving differentially expressed transcripts. Bovine digital dermatitis lesions had increased expression of mRNA for a2-macroglobulin-like 1, a protein potentially involved in bacterial immune evasion and bacterial survival. There was increased expression of keratin 6A and interleukin 1b mRNA in bovine digital dermatitis lesions, but reduced expression of most other keratin and keratin-associated genes. There was little evidence of local immune reactions to the bacterial infection present in lesions. Ten samples were processed; five normal skin biopsies from the hind foot skin and five digital dermatitis lesions (large (>2cm) red raw in appearance).
Project description:Digital dermatitis is a painful foot disease compromising welfare in dairy cattle. The disease has a complex multibacterial aetiology, but little is known about its pathogenesis. In this study, gene expression in skin biopsies from five bovine digital dermatitis lesions and five healthy bovine feet was compared using RNA-Seq technology. Differential gene expression was determined after mapping transcripts to the Btau 4.0 genome. Pathway analysis identified gene networks involving differentially expressed transcripts. Bovine digital dermatitis lesions had increased expression of mRNA for a2-macroglobulin-like 1, a protein potentially involved in bacterial immune evasion and bacterial survival. There was increased expression of keratin 6A and interleukin 1b mRNA in bovine digital dermatitis lesions, but reduced expression of most other keratin and keratin-associated genes. There was little evidence of local immune reactions to the bacterial infection present in lesions.
Project description:We examined 36 biopsies taken from digital dermatitis lesions of Holstein cows. The target was the V3 -V4 variable region of 16S rRNA using Treponema specific primers. We identified 20 different taxa of Treponema using this approach. Phylogenetic study of the Treponema taxa found in digital dermatitis lesions of Holstein cows.
Project description:Here, we report the first complete genomes of three cultivable treponeme species from bovine digital dermatitis (DD) skin lesions, two comparative human treponemes and a bovine gastrointestinal (GI) isolate. Key genomic differences between bovine and human treponemes implicate microbial mechanisms that enhance knowledge of how DD, a severe disease of ruminants, has emerged into a prolific and endemic disease in countries worldwide. Bovine DD treponemes have additional oxidative stress genes compared to nearest human-isolated relatives, suggesting better toleration of oxidative stress, and thus potentially explaining the ability of bovine strains to colonize skin surfaces. Comparison of bovine DD and GI treponemes as well as bovine pathogenic and human non-pathogenic saprophyte Treponema phagedenis strains indicates genes encoding a five-enzyme biosynthetic pathway for the production of 2,3-diacetamido-2,3-dideoxy-d-mannuronic acid, a rare di-N-acetylated mannuronic acid sugar with potential immunomodulatory activity, as important for pathogenesis. The bovine T. phagedenis strains further differed from human strains by having a larger number of unique genetic features including components of a type IV secretion system and a phosphate utilisation system including phoU, a gene associated with enhanced osmotic stress survival. Proteomic analyses confirmed bovine derived T. phagedenis exhibits expression of PhoU but not the putative secretion system whilst the novel mannuronic acid pathway was expressed in near entirety across the DD treponemes. Analysis of osmotic stress response in water identified a difference between bovine and human T. phagedenis with bovine strains surviving better. This novel mechanism could enable a selective advantage, allowing environmental persistence and transmission of bovine T. phagedenis. Finally, we investigated a range of treponeme genes encoding ortholog families across the DD treponemes representing putative outer membrane proteins (OMPs) and identified several families as multi-specific adhesins capable of binding extra cellular matrix (ECM) components. Human saprophytic T. phagedenis could not be differentiated from bovine pathogenic strains by these adhesins and only two of ten characterised ortholog OMP families were absent from commensal bovine treponemes. One of these bovine pathogen specific adhesin ortholog families showed considerable diagnostic potential with the Treponema medium representative demonstrating the greatest disease specificity (91.6%). This work has shed light on treponeme host adaptation and has identified candidate molecules for future diagnostics, vaccination and therapeutic intervention.
Project description:With regulatory roles in development, cell proliferation and disease, micro-RNA (miRNA) biology is of great importance and a potential key to novel RNA-based therapeutic regimens. Biochemically based sequencing approaches have provided robust means of uncovering miRNA binding landscapes on transcriptomes of various species. However, a current limitation to the therapeutic potential of miRNA biology in cattle is the lack of validated miRNAs targets. Here, we use cross-linking immunoprecipitation (CLIP) of the Argonaute (AGO) proteins and unambiguous miRNA-target identification through RNA chimeras to define a regulatory map of miRNA interactions in the cow (Bos taurus). The resulting interactome is the deepest reported to date for any species, demonstrating that comprehensive maps can be empirically obtained. We observe that bovine miRNA targeting principles are consistent with those observed in other mammals. Motif and structural analyses define expanded pairing rules with most interactions combining seed-based pairing with distinct, miRNA-specific patterns of auxiliary pairing. Further, miRNA-target chimeras had predictive value in evaluating true regulatory sites of the miR-17 family. Finally, we define miRNA-specific targeting for >5000 mRNAs and determine gene ontologies (GO) for these targets. This confirmed repression of genes important for embryonic development and cell cycle progress by the let-7 family, and repression of those involved in cell cycle arrest by the miR-17 family, but it also suggested a number of unappreciated miRNA functions. Our results provide a significant resource for transcriptomic understanding of bovine miRNA regulation, and demonstrate the power of experimental methods for establishing comprehensive interaction maps.