A TEST OF FOOD PARTITIONING BETWEEN THE AQUATIC LARVAE OF TWO PARAPATRIC SPECIES OF TWO-LINED SALAMANDER (EURYCEA BISLINEATA SPECIES COMPLEX) IN A ZONE OF SYMPATRIC CONTACT

Phylogenetically related species with similar ecologies often partition resources when in sympatry. Food is an important factor in the co-occurrence of sympatric salamanders, and food partitioning occurs in a variety of sympatric, similar species. Several members of the Two-lined Salamander (Eurycea bislineata) species complex are largely parapatric but co-exist within a narrow zone of sympatric contact. Because larvae of these salamanders frequently occur in very high densities, we tested the hypothesis that larvae of the Blue Ridge Salamander (E. wilderae) and the Southern Two-lined Salamander (E. cirrigera) partition food in sympatry in northeastern Georgia. We predicted that the diets of these two species would differ in sympatry and that the respective diet of each species would differ between allopatric and sympatric populations. Both species fed largely on the aquatic larvae of Trichoptera and Diptera, and their diets reflected the available insect fauna of the respective streams. There was no significant difference between the species in sympatry or between allopatric and sympatric populations of either species. Although we found no evidence of food partitioning, we cannot rule out interspecific competition that may manifest itself in some resource other than food

The importance of comparative phylogeography in diagnosing introduced species: a lesson from the seal salamander, Desmognathus monticola

<p>Abstract</p> <p>Background</p> <p>In most regions of the world human influences on the distribution of flora and fauna predate complete biotic surveys. In some cases this challenges our ability to discriminate native from introduced species. This distinction is particularly critical for isolated populations, because relicts of native species may need to be conserved, whereas introduced species may require immediate eradication. Recently an isolated population of seal salamanders, <it>Desmognathus monticola</it>, was discovered on the Ozark Plateau, ~700 km west of its broad continuous distribution in the Appalachian Mountains of eastern North America. Using Nested Clade Analysis (NCA) we test whether the Ozark isolate results from population fragmentation (a natural relict) or long distance dispersal (a human-mediated introduction).</p> <p>Results</p> <p>Despite its broad distribution in the Appalachian Mountains, the primary haplotype diversity of <it>D. monticola </it>is restricted to less than 2.5% of the distribution in the extreme southern Appalachians, where genetic diversity is high for other co-distributed species. By intensively sampling this genetically diverse region we located haplotypes identical to the Ozark isolate. Nested Clade Analysis supports the hypothesis that the Ozark population was introduced, but it was necessary to include haplotypes that are less than or equal to 0.733% divergent from the Ozark population in order to arrive at this conclusion. These critical haplotypes only occur in < 1.2% of the native distribution and NCA excluding them suggest that the Ozark population is a natural relict.</p> <p>Conclusion</p> <p>Our analyses suggest that the isolated population of <it>D. monticola </it>from the Ozarks is not native to the region and may need to be extirpated rather than conserved, particularly because of its potential negative impacts on endemic Ozark stream salamander communities. Diagnosing a species as introduced may require locating nearly identical haplotypes in the known native distribution, which may be a major undertaking. Our study demonstrates the importance of considering comparative phylogeographic information for locating critical haplotypes when distinguishing native from introduced species.</p

miR-155 in the progression of lung fibrosis in systemic sclerosis

Background\ud MicroRNA (miRNA) control key elements of mRNA stability and likely contribute to the dysregulated lung gene expression observed in systemic sclerosis associated interstitial lung disease (SSc-ILD). We analyzed the miRNA gene expression of tissue and cells from patients with SSc-ILD. A chronic lung fibrotic murine model was used.\ud \ud Methods\ud RNA was isolated from lung tissue of 12 patients with SSc-ILD and 5 controls. High-resolution computed tomography (HRCT) was performed at baseline and 2–3 years after treatment. Lung fibroblasts and peripheral blood mononuclear cells (PBMC) were isolated from healthy controls and patients with SSc-ILD. miRNA and mRNA were analyzed by microarray, quantitative polymerase chain reaction, and/or Nanostring; pathway analysis was performed by DNA Intelligent Analysis (DIANA)-miRPath v2.0 software. Wild-type and miR-155 deficient (miR-155ko) mice were exposed to bleomycin.\ud \ud Results\ud Lung miRNA microarray data distinguished patients with SSc-ILD from healthy controls with 185 miRNA differentially expressed (q < 0.25). DIANA-miRPath revealed 57 Kyoto Encyclopedia of Genes and Genomes pathways related to the most dysregulated miRNA. miR-155 and miR-143 were strongly correlated with progression of the HRCT score. Lung fibroblasts only mildly expressed miR-155/miR-21 after several stimuli. miR-155 PBMC expression strongly correlated with lung function tests in SSc-ILD. miR-155ko mice developed milder lung fibrosis, survived longer, and weaker lung induction of several genes after bleomycin exposure compared to wild-type mice.\ud \ud Conclusions\ud miRNA are dysregulated in the lungs and PBMC of patients with SSc-ILD. Based on mRNA-miRNA interaction analysis and pathway tools, miRNA may play a role in the progression of the disease. Our findings suggest that targeting miR-155 might provide a novel therapeutic strategy for SSc-ILD

The structure of KPN03535 (gi|152972051), a novel putative lipoprotein from Klebsiella pneumoniae, reveals an OB-fold

KPN03535 is a protein unique to K. pneumoniae. The crystal structure reveals that KPN03535 represents a novel variant of the OB-fold and is likely to be a DNA-binding lipoprotein

The structure of the first representative of Pfam family PF09836 reveals a two-domain organization and suggests involvement in transcriptional regulation

The crystal structure of the NGO1945 gene product from N. gonorrhoeae (UniProt Q5F5IO) reveals that the N-terminal domain assigned as a domain of unknown function (DUF2063) is likely to bind DNA and that the protein may be involved in transcriptional regulation

The stigma turbine:A theoretical framework for conceptualizing and contextualizing marketplace stigma

Stigmas, or discredited personal attributes, emanate from social perceptions of physical characteristics, aspects of character, and “tribal” associations (e.g., race; Goffman 1963). Extant research emphasizes the perspective of the stigma target, with some scholars exploring how social institutions shape stigma. Yet the ways stakeholders within the socio-commercial sphere create, perpetuate, or resist stigma remain overlooked. We introduce and define marketplace stigma as the labeling, stereotyping, and devaluation by and of commercial stakeholders (consumers, companies and their employees, stockholders, institutions) and their offerings (products, services, experiences). We offer the Stigma Turbine (ST) as a unifying conceptual framework that locates marketplace stigma within the broader sociocultural context, and illuminates its relationship to forces that exacerbate or blunt stigma. In unpacking the ST, we reveal the critical role market stakeholders can play in (de)stigmatization, explore implications for marketing practice and public policy, and offer a research agenda to further our understanding of marketplace stigma and stakeholder welfare

Role of temperature in determining relative abundance in cave twilight zones by two species of lungless salamander (family Plethodontidae)

Lungless salamanders of the family Plethodontidae have historically been considered to be passive conformers to their surrounding thermal environment because there is no evidence that they thermoregulate behaviourally in the field. In contrast, plethodontids readily choose optimal temperatures when placed on experimental thermal gradients. It has been hypothesized that restriction to moist habitats prevents these salamanders from exploiting thermally diverse microhabitats in nature. We tested this hypothesis, as well as the hypothesis that response to temperature differs among plethodontid species, by investigating the thermal ecology of two species (Cave Salamander, Eurycea lucifuga Rafinesque, 1822, and Northern Slimy Salamander, Plethodon glutinosus (Green, 1818)) occupying twilight zones of six caves in northwestern Georgia. We recorded inside and outside temperatures, as well as the number of each species, for each of three seasons (summer, fall, spring) over 13 years. We also tested for differences in thermal preference along experimental gradients in the laboratory. We further generated environmental niche models (ENMs) to investigate the potential role of abiotic variables, including environmental temperature, in determining the geographic range of each species. We found that both species responded to cave temperature in such a way as to suggest that these salamanders thermoregulate behaviourally when given a diversity of thermal options within a relatively constant moisture regime. We also determined that E. lucifuga prefers lower temperatures than P. glutinosus. ENM analysis indicated that, while abiotic variables both strongly influence the ecological niche of both species, the range of E. lucifuga is strongly predicted by them. The geographic distribution of P. glutinosus is apparently heavily influenced by the presence of closely related, contiguous neighbors with similar niche requirements

Role of temperature in determining relative abundance in cave twilight zones by two species of lungless salamander (family Plethodontidae)

Lungless salamanders of the family Plethodontidae have historically been considered to be passive conformers to their surrounding thermal environment because there is no evidence that they thermoregulate behaviourally in the field. In contrast, plethodontids readily choose optimal temperatures when placed on experimental thermal gradients. It has been hypothesized that restriction to moist habitats prevents these salamanders from exploiting thermally diverse microhabitats in nature. We tested this hypothesis, as well as the hypothesis that response to temperature differs among plethodontid species, by investigating the thermal ecology of two species (Cave Salamander, Eurycea lucifuga Rafinesque, 1822, and Northern Slimy Salamander, Plethodon glutinosus (Green, 1818)) occupying twilight zones of six caves in northwestern Georgia. We recorded inside and outside temperatures, as well as the number of each species, for each of three seasons (summer, fall, spring) over 13 years. We also tested for differences in thermal preference along experimental gradients in the laboratory. We further generated environmental niche models (ENMs) to investigate the potential role of abiotic variables, including environmental temperature, in determining the geographic range of each species. We found that both species responded to cave temperature in such a way as to suggest that these salamanders thermoregulate behaviourally when given a diversity of thermal options within a relatively constant moisture regime. We also determined that E. lucifuga prefers lower temperatures than P. glutinosus. ENM analysis indicated that, while abiotic variables both strongly influence the ecological niche of both species, the range of E. lucifuga is strongly predicted by them. The geographic distribution of P. glutinosus is apparently heavily influenced by the presence of closely related, contiguous neighbors with similar niche requirements