Evolutionary Reconstructions of the Transferrin Receptor of Caniforms Supports Canine Parvovirus Being a Re-emerged and Not a Novel Pathogen in Dogs

Parvoviruses exploit transferrin receptor type-1 (TfR) for cellular entry in carnivores, and specific interactions are key to control of host range. We show that several key mutations acquired by TfR during the evolution of Caniforms (dogs and related species) modified the interactions with parvovirus capsids by reducing the level of binding. These data, along with signatures of positive selection in the TFRC gene, are consistent with an evolutionary arms race between the TfR of the Caniform clade and parvoviruses. As well as the modifications of amino acid sequence which modify binding, we found that a glycosylation site mutation in the TfR of dogs which provided resistance to the carnivore parvoviruses which were in circulation prior to about 1975 predates the speciation of coyotes and dogs. Because the closely-related black-backed jackal has a TfR similar to their common ancestor and lacks the glycosylation site, reconstructing this mutation into the jackal TfR shows the potency of that site in blocking binding and infection and explains the resistance of dogs until recent times. This alters our understanding of this well-known example of viral emergence by indicating that canine parvovirus emergence likely resulted from the re-adaptation of a parvovirus to the resistant receptor of a former host.     

Detection of a Novel Bovine Lymphotropic Herpesvirus

Degenerate PCR primers which amplify a conserved region of the DNA polymerase genes of the herpesvirus family were used to provide sequence evidence for a new bovine herpesvirus in bovine B-lymphoma cells and peripheral blood mononuclear cells (PBMC). The sequence of the resultant amplicon was found to be distinct from those of known herpesvirus isolates. Alignment of amino acid sequences demonstrated 70% identity with ovine herpesvirus 2, 69% with alcelaphine herpesvirus 1, 65% with bovine herpesvirus 4, and 42% with bovine herpesvirus 1. Phylogenetic analysis placed this putative virus within the tumorigenic Gammaherpesvirinae subfamily, and it is tentatively identified as bovine lymphotropic herpesvirus. This novel agent was expressed in vitro from infected PBMC, and cell-free supernatants were used to transfer infection to a bovine B-cell line, BL3. Analysis, with specific PCR primers, of DNA from bovine PBMC and lymphoma cells identified infection in blood of 91% of adult animals (n = 101), 63% of lymphomas (n = 32), and 38% of juveniles (n = 13). Of the adults, herpesvirus infection was present in 94% of animals that were seropositive for bovine leukemia virus (BLV) (n = 63) and in 87% of BLV-seronegative animals (n = 38). Of the seropositive group, 17 animals exhibited persistent lymphocytosis, and 100% of these were herpesvirus positive by PCR. A role for bovine lymphotropic herpesvirus as a cofactor in BLV pathogenesis is considered.     

A computer simulation of transcription and processing of eucaryotic mRNA.

Ecological stability defined as the ability of an ecosystem to resist changes in the presence of perturbations leads to consideration of the effective choice of the pathways for energy flow. The roles of diversity and complexity (i.e. interdependence) in determining stability arise naturally in the development of an index from the qualitative concepts of information theory. As a tool for ecosystem analysis, the stability measure developed in this paper is applied to two example systems.     

Trehalose as an endogenous reserve in spores of the fungus Myrothecium verrucaria

Mandels, G. R. (U.S. Army Natick Laboratories, Natick, Mass.), Rasma Vitols, and Frederick W. Parrish. Trehalose as an endogenous reserve in spores of the fungus Myrothecium verrucaria. J. Bacteriol. 90:1589-1598. 1965.-Gross analysis of Myrothecium verrucaria spores showed approximately 3% fat, 33% carbohydrate, and 9.5% nitrogen. The water-soluble carbohydrates were trehalose, glucose, mannitol, and an unidentified phosphorylated compound. Water-soluble amino acids include leucine or norleucine (or both), valine, gamma-amino-n-butyric acid, beta-amino-n-butyric acid, ergothionine, glutamic acid, glutamine, glycine, aspartic acid, asparagine, cystine, and cystathionine. Ergosterol was also present. alphaalpha-Trehalose is the major reserve (20% of the dry weight), although approximately 30% of it appeared to be at the spore surface and was released by nonlethal treatment with 0.1 n HCl. Treatment with toluene or exposure to heat sufficient to kill the spores (20 min at 60 C) caused rapid liberation of all of the trehalose. Although spores could utilize exogenous trehalose with no appreciable lag, some stimulus, such as exposure to heat (10 min at 55 C), incubation with azide, or germination on exogenous substrates, was necessary to effect utilization of trehalose reserves. Spores have trehalase, but it is apparently at the spore surface, since it is inactivated by acid treatment which does not kill the spores. The metabolic pathway for utilization of trehalose is not known, but presumably it is not mediated by trehalase. The involvement of mannitol is indicated, since it tends to increase as trehalose decreases, although the changes are not quantitatively equivalent.     

Potent Inhibition of Pseudogymnoascus destructans,the Causative Agent of White-Nose Syndrome in Bats,by Cold-Pressed,Terpeneless, Valencia Orange Oil

The causative agent of White-nose Syndrome (WNS), Pseudogymnoascus destructans, has been shown to be fatal to several species of bats in North America. To date, no compounds or chemical control measures have been developed which eliminates the growth of the fungus in the environment or in affected animals. In the current study, we evaluated the activity of cold-pressed, terpeneless orange oil (CPT) against multiple isolates of P. destructans in vitro. For all assays, a modified Kirby-Bauer disk diffusion assay was used. Standardized spore suspensions were prepared, adjusted to a specific optical density, and used to plate fungal lawns. Plates were incubated at either 15°C or 4°C for up to 6 months and checked at regular intervals for growth. Once controls had grown, zones of inhibition were measured (mm) on test plates and compared to those obtained using current antifungal drugs. All P. destructans isolates were completely inhibited by 100% CPT (10 μL) at 1 month of incubation regardless of temperature (4°C and 15°C). Complete inhibition persisted up to 6 months following a single exposure at this concentration. Of the standard antifungals, only amphotericin B demonstrated any activity, resulting in zone diameters ranging from 58 mm to 74 mm. CPT, at the highest concentration tested (100%), had no significant effect against a variety of other environmental organisms including various filamentous fungi, bacteria and aerobic actinomycetes. Given that CPT is relatively non-toxic, the possibility exists that the all-natural, mixture could be used as an environmental pre-treatment to eradicate P. destructans from bat habitats. Additional studies are needed to assess any undesirable effects of CPT on bat behavior and health and overall impacts on other members of the interconnected ecosystem(s).     

Issues in using whole slide imaging for diagnostic pathology: “routine” stains,immunohistochemistry and predictive markers

The traditional microscope, together with the “routine” hematoxylin and eosin (H & E) stain, remains the “gold standard” for diagnosis of cancer and other diseases; remarkably, it and the majority of associated biological stains are more than 150 years old. Immunohistochemistry has added to the repertoire of “stains” available. Because of the need for specific identification and even measurement of “biomarkers,” immunohistochemistry has increased the demand for consistency of performance and interpretation of staining results. Rapid advances in the capabilities of digital imaging hardware and software now offer a realistic route to improved reproducibility, accuracy and quantification by utilizing whole slide digital images for diagnosis, education and research. There also are potential efficiencies in work flow and the promise of powerful new analytical methods; however, there also are challenges with respect to validation of the quality and fidelity of digital images, including the standard H & E stain, so that diagnostic performance by pathologists is not compromised when they rely on whole slide images instead of traditional stained tissues on glass slides.     

Gastric evacuation rates of white perch,Morone americana,determined from laboratory and field data

Synopsis Gastric evacuation rates (R) of white perch,Morone americana, were determined in laboratory experiments and by using field data. The resulting relationship ofR and temperature (T) for white perch wasR = 0.028e^0.106T (r² = 0.98). The high r² of the regression indicates good agreement of the combined laboratory and field data. Our rate compares well with those available for other species; and especially for Eurasian perch, which has a similar thermal existence to white perch in Lake Erie.     

Impact of seasonality,storage of semen,and sperm head‐shape on whole tissue methylation and expression of methylation responsive candidate genes in swine placenta and fetal livers from summer and winter breedings

Epigenetics includes the study of external factors that can influence the expression of genes by altering the accessibility of DNA through methylation. To investigate the epigenetic influence of season, sperm head shape, and semen storage on placental and fetal tissues, pregnancies were generated in the summer or winter using boar semen from either least or most sperm head shape change, collected during cool or warm seasons, and stored as cooled‐extended or cryopreserved. The lowest (p < 0.05) ratios of 5‐methylcytosine to 5‐hydroxymethylcytosine activity (5mC:5hmC) in fetal liver were from summer breedings and in placental tissues from winter breedings. The relative expression of placental CDH1 tended ( p < 0.10) to be greater in placenta generated from cryopreserved semen or semen collected during cool periods. The relative expression of placental GNAS was affected ( p < 0.05) by the interaction of breeding and semen collection seasons. Cryopreserved semen increased ( p < 0.05) the placental relative expression of GNAS. Placental MEST and RHOBTB3 tended ( p < 0.10) to have a greater relative expression from pregnancies generated using semen collected during cool periods used during winter breedings. Within fetal liver, the relative expression of GNAS and HGF was greater ( p < 0.05) from winter breedings. Interaction of winter breedings and least sperm head shape change tended ( p < 0.10) to have the greatest fetal liver expression of CDH1. Seasonality of semen collection, breeding, and the effect on sperm head shape change had an influence on the expression of genes with known differentially methylated regions or response to methylation activity from embryonic and extraembryonic tissues.