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The mountain pine beetle (MPB; Dendroctonus ponderosae) is a forest insect pest that attacks several different pine (Pinus) species in its native range of distribution in western North America. MPB are exposed for most of their life cycle to the chemical defenses of their hosts. These defenses are dominated by oleoresin secretions containing mostly various monoterpenes and diterpene resin acids (DRAs). Cytochrome P450 enzymes (P450s) of the MPB are thought to be involved in the metabolism of at least some of these defense compounds. Here we describe the cloning and characterization of three MPB P450s, CYP6DJ1, CYP6BW1 and CYP6BW3, and their functions in the oxidation of various monoterpenes and diterpene resin acids. CYP6DJ1 oxidizes the monoterpenes (+)-(4R)-limonene, (–)-(4S)-limonene and terpinolene and produces (4R,8R)-limonene-8,9-epoxide, (4R,8S)-limonene-8,9-epoxide, (4S,8S)-limonene-8,9-epoxide, (4S,8R)-limonene-8,9-epoxide, perilla alcohol and several unidentified oxidized compounds. These products of CYP6DJ1 were also identified in extracts of MPB treated with the same monoterpenes. CYP6BW1 and CYP6BW3 both oxidize the DRAs abietic acid, dehydroabietic acid, neoabietic acid, levopimaric acid, palustric acid, and isopimaric acid, producing hydroxylated and epoxidized DRAs. CYP6DJ1, CYP6BW1 and CYP6BW3 appear to contribute to the metabolism of oleoresin terpenes as part of the MPB’s ability to cope with host defenses. [ABSTRACT FROM AUTHOR]

Accurate species delimitation and description are necessary to guide effective conservation of imperiled species, and this synergy is maximized when multiple data sources are used to delimit species. We illustrate this point by examining Drymarchon couperi (Eastern Indigo Snake), a large, federally-protected species in North America that was recently divided into two species based on gene sequence data from three loci and heuristic morphological assessment. Here, we re-evaluate the two-species hypothesis for D. couperi by evaluating both population genetic and gene sequence data. Our analyses of 14 microsatellite markers revealed 6–8 genetic population clusters with significant admixture, particularly across the contact zone between the two hypothesized species. Phylogenetic analyses of gene sequence data with maximum-likelihood methods suggested discordance between mitochondrial and nuclear markers and provided phylogenetic support for one species rather than two. For these reasons, we place Drymarchon kolpobasileus into synonymy with D. couperi. We suggest inconsistent patterns between mitochondrial and nuclear DNA are driven by high dispersal of males relative to females. We advocate for species delimitation exercises that evaluate admixture and gene flow in addition to phylogenetic analyses, particularly when the latter reveal monophyletic lineages. This is particularly important for taxa, such as squamates, that exhibit strong sex-biased dispersal. Problems associated with over-delimitation of species richness can become particularly acute for threatened and endangered species, because of high costs to conservation when taxonomy demands protection of more individual species than are supported by accumulating data. [ABSTRACT FROM AUTHOR]

Non-alcoholic fatty liver disease has become the leading liver disease in North America and is associated with the progressive inflammatory liver disease non-alcoholic steatohepatitis (NASH). Considerable effort has been made to understand the role of resident and recruited macrophage populations in NASH however numerous questions remain. Our goal was to characterize the dynamic changes in liver macrophages during the initiation of NASH in a murine model. Using the methionine-choline deficient diet we found that liver-resident macrophages, Kupffer cells were lost early in disease onset followed by a robust infiltration of Ly-6C+ monocyte-derived macrophages that retained a dynamic phenotype. Genetic profiling revealed distinct patterns of inflammatory gene expression between macrophage subsets. Only early depletion of liver macrophages using liposomal clodronate prevented the development of NASH in mice suggesting that Kupffer cells are critical for the orchestration of inflammation during experimental NASH. Increased understanding of these dynamics may allow us to target potentially harmful populations whilst promoting anti-inflammatory or restorative populations to ultimately guide the development of effective treatment strategies. [ABSTRACT FROM AUTHOR]

Recently bats have been associated with the emergence of diseases, both as reservoirs for several new viral diseases in humans and other animals and, in the northern Americas, as hosts for a devastating fungal disease that threatens to drive several bat species to regional extinction. However, despite these catastrophic events little Information is available on bat defences or how they interact with their pathogens. Even less is known about the response of bats to infection during torpor or long-term hibernation. Using tissue samples collected at the termination of an experiment to explore the pathogenesis of White Nose Syndrome in Little Brown Bats, we determined if hibernating bats infected with the fungus Pseudogymnoascus destructans could respond to infection by activating genes responsible for innate immune and stress responses. Lesions due to fungal infection and, in some cases, secondary bacterial infections, were restricted to the skin. However, we were unable to obtain sufficient amounts of RNA from these sites. We therefore examined lungs for response at an epithelial surface not linked to the primary site of infection. We found that bats responded to infection with a significant increase in lungs of transcripts for Cathelicidin (an anti-microbial peptide) as well as the immune modulators tumor necrosis factor alpha and interleukins 10 and 23. In conclusion, hibernating bats can respond to experimental P. destructans infection by activating expression of innate immune response genes. [ABSTRACT FROM AUTHOR]