Methylation of cytosines is a prototypic epigenetic modification of the DNA. It has been implicated in various regulatory mechanisms across the animal kingdom and particularly in vertebrates. We mapped DNA methylation in 580 animal species (535 vertebrates, 45 invertebrates), resulting in 2443 genome-scale DNA methylation profiles of multiple organs. Bioinformatic analysis of this large dataset quantified the association of DNA methylation with the underlying genomic DNA sequence throughout vertebrate evolution. We observed a broadly conserved link with two major transitions—once in the first vertebrates and again with the emergence of reptiles. Cross-species comparisons focusing on individual organs supported a deeply conserved association of DNA methylation with tissue type, and cross-mapping analysis of DNA methylation at gene promoters revealed evolutionary changes for orthologous genes. In summary, this study establishes a large resource of vertebrate and invertebrate DNA methylomes, it showcases the power of reference-free epigenome analysis in species for which no reference genomes are available, and it contributes an epigenetic perspective to the study of vertebrate evolution.
The red fox (Vulpes vulpes) is a widespread species, harbouring many pathogens relevant for humans and pets. Indeed, Anaplasma spp., Ehrlichia canis and Rickettsia spp. among the bacteria and Hepatozoon canis as well as Babesia sp. among the parasites have been the focus of several studies. In a cohort of 36 foxes shot on one day in the north-eastern part of Austria, Babesia microti-like pathogens were found in 50%, while H. canis was detected in 58.3% of the samples. The spleen was more useful for detection of H. canis, whereas B. microti-like parasites were more frequently found in the blood. Bacteria could not be confirmed in any of the cases to demonstrate the occurrence of such tick-borne pathogens using PCR and sequencing on blood and spleen samples. The occurrence of B. microti-like and H. canis parasites raised many questions, because these infections have never been found autochthonously in dogs. Furthermore in the case of H. canis the main vector tick, Rhipicephalus sanguineus, is absent in the sampling area, leaving space for further hypotheses for transmission such as vertical transmission, transmission via ingestion of prey animals or other vector ticks. Further studies are needed to evaluate the risks for pets in this area. PCRs delivered differing results with the different tissues, suggesting the use of both spleen and blood to obtain an integral result.
Background: A sudden decline of the European brown hare ( Lepus europaeus ) population in one of the best hunting districts for small game species in northern Germany, the German North-Sea island Pellworm, in the years 2007/08 following marked habitat changes led to the implementation of a thorough health assessment program of the population. 110 animals were collected during the normal hunting season in the years 2010 and 2011. A post-mortem examination and histopathological investigation was performed on all animals. Additionally, routine bacteriology of the small intestine and parasitology were carried out. Sera of hares were tested for European Brown Hare Syndrome (EBHS) by enzyme linked immunosorbent assay, and for Treponema sp. by indirect immunofluorescent test. Additional testing was performed when deemed necessary. Results: The most striking result was a shift in the intestinal bacterial flora towards Gram-negative Enterobacteriaceae with a predominance of either Escherichia coli , or Aeromonas sp., or a high-grade double-infection with these two pathogens with subsequent catarrhal enteritis. Additionally, a marked coccidiosis, and varying infestations with the nematode Trichostrongylus retortaeformis were found. The sero-prevalence for EBHS was 78.1%, and for Treponema 43.9%. Conclusions: The shift and decrease in diversity of the intestinal flora was the main and most consistent result found. In the authors’ opinion the change of the habitat combined with other stressors increased the animals’ sensitivity to ubiquitous bacterial species and parasites which usually would not have such fatal effects.
Diseases of the gastrointestinal tract due to changes in the bacterial flora have been described with increasing incidence in the European brown hare. Despite extensive demographic and phylogeographic research, little is known about the composition of its gut microbiota and how it might vary based on potential environmental or host factors. We analysed the intestinal and faecal microbiota of 3 hare populations by Illumina MiSeq 16S rRNA gene amplicon sequencing. The phyla and OTU abundance composition differed significantly between intestinal and faecal samples (PERMANOVA:P = 0.002 andP = 0.031, respectively), but in both sample typesFirmicutesandBacteroidetesdominated the microbial community composition (45.51% and 19.30% relative abundance). Intestinal samples contained an enrichment ofProteobacteriacompared with faecal samples (15.71-fold change,P < 0.001). At OTU level, a significant enrichment with best BLAST hits to theEscherichia-Shigellagroup,Eubacterium limosum,Sphingomonas kyeonggiensis,Flintibacter butyricusandBlautia faeciswere detected in intestinal samples (P < 0.05). In our statistical model, geographic location and possibly associated environmental factors had a greater impact on the microbiota composition than host factors. Population had a significant effect on the composition of abundant intestinal and faecal OTUs, and on the abundance of potential pathogenic bacteria of the familyEnterobacteriaceae, regularly associated with intestinal dysbiosis in hares, in faecal samples. Our study is the first to describe the microbiota in brown hares and provides a foundation to generate hypothesis aiming to test the role of gut health in population fluctuations of the species.
The infrequent mention of epipharyngeal pouches occurring in some species of bears indicates the scarcity of morphological and functional knowledge about these structures. In order to provide precise morphological data on the structure of these remarkable formations and to verify their taxonomic utility, the pharyngeal regions of 1 spectacled bear and 3 brown bears were examined. All these individuals possessed epipharyngeal pouches, which are tubular, blind‐ending outpouchings of the caudodorsal pharyngeal wall equipped with respiratory epithelium and a thick layer of elastic fibres. While the spectacled bear and Ursus arctos syriacus possessed a single pouch on the caudodorsal wall of the nasopharynx, in Ursus arctos and Ursus arctos beringianus 2 unequally sized pouches were present. Two additional sacs of smaller size, representing outpouchings of the lateral pharyngeal wall, occurred in the spectacled bear. These findings prove epipharyngeal pouches to be constant and unique morphological features of the family Ursidae, the anatomical features suggesting involvement in the respiratory system most probably in important aspects of ursid phonation. This is the first description of epipharyngeal pouches in the spectacled bear.
1 March 2003 in Journal of Zoo and Wildlife Medicine
Numerous cases of ataxia, hind limb paresis, and paralysis have occurred in cheetah (Acinonyx jubatus) cubs over the past 10 yr within the European Endangered Species Program population, including 12 in mainland Europe, two in the British Isles, one in Namibia, and one in Dubai. The condition is the most important medical factor limiting European cheetah population growth. Eight cubs at the Salzburg Zoo, Austria, were affected. They demonstrated upper motor neuron lesions when alive and bilateral, symmetrical myelin degeneration of the spinal cord on necropsy. Ballooning of myelin sheaths surrounded mostly preserved axons, and no spheroids, characteristic of acute axonal degeneration, were found. Myelin loss markedly exceeded axonal degeneration. The syndrome's etiology is unclear, although viral, bacterial, parasitic, genetic, nutritional-metabolic, toxic, and physical causes have been considered.