Diet and Prey Selection of Dholes in Evergreen and Deciduous Forests of Southeast Asia

Endangered dholes (Cuon alpinus) are restricted to small and declining populations in Southeast Asia, and little is known about how their ecology differs within the region. We used DNA-confirmed scats and prey surveys to determine the seasonal diet and prey selection of dholes in 2 different landscapes that dominate Southeast Asia: closed evergreen forests in hilly terrain in northern Laos, and open deciduous forests in relatively flat terrain in eastern Cambodia. On both sites, muntjac (Muntiacus spp.; 20–28 kg) was the dominant prey item and was selectively consumed over other ungulates in all seasons. Our findings differ from previous conclusions, based largely on studies from India, that the preferred prey weight range of dholes was either 40–60 kg or 130–190 kg. Other important prey were sambar (Rusa unicolor) in Laos, and wild pig (Sus scrofa) and banteng (Bos javanicus) in Cambodia. Seasonal differences in overall diet occurred in Laos, but not Cambodia, primarily because of an increase in livestock consumption. The mean number of dhole scats in group defecation sites was higher in Cambodia (5.9 ± 0.5 [SE]) than Laos (2.4 ± 0.2), suggesting pack sizes were larger in Cambodia. Our results suggest that regardless of land cover type, prey diversity, or pack size, the management of muntjac will be important for conserving dhole populations in Southeast Asia. In Laos, we recommend that local villagers remove livestock from the protected area during the hot-dry season to reduce livestock predation by dholes. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.     

From clinical specimens to human cancer preclinical models—a journey the NCI-cell line database—25 years later

The intramural the National Cancer Institute (NCI) and more recently the University of Texas Southwestern Medical Center with many different collaborators comprised a complex, multi-disciplinary team that collaborated to generated large, comprehensively annotated, cell-line related research resources which includes associated clinical, and molecular characterization data. This material has been shared in an anonymized fashion to accelerate progress in overcoming lung cancer, the leading cause of cancer death across the world. However, this cell line collection also includes a range of other cancers derived from patient-donated specimens that have been remarkably valuable for other types of cancer and disease research. A comprehensive analysis conducted by the NCI Center for Research Strategy of the 278 cell lines reported in the original Journal of Cellular Biochemistry Supplement, documents that these cell lines and related products have since been used in more than 14 000 grants, and 33 207 published scientific reports. This has resulted in over 1.2 million citations using at least one cell line. Many publications involve the use of more than one cell line, to understand the value of the resource collectively rather than individually; this method has resulted in 2.9 million citations. In addition, these cell lines have been linked to 422 clinical trials and cited by 4700 patents through publications. For lung cancer alone, the cell lines have been used in the research cited in the development of over 70 National Comprehensive Cancer Network clinical guidelines. Finally, it must be underscored again, that patient altruism enabled the availability of this invaluable research resource.     

Exosome DNA: Critical regulator of tumor immunity and a diagnostic biomarker

Nanosized cellular vesicles “exosome” contains a variety of biological cargo including DNA fragments from cell-of-origin. Despite its biological stability and clinical utility in tumor diagnosis, exosome DNA (ExoDNA) is very little studied as compare with exosome RNA. Cytoplasmic accumulation of damaged DNA from nucleus and mitochondria often leads to its packaging in exosomes by yet unknown pathways. ExoDNA modulates tumor immunity via paracrine interactions and activation of cytosolic DNA sensor pathways, for example, STING, cGAS, and so forth in specific immune cell subsets. In addition to priming tumor immunity, ExoDNA is also emerging as a critical regulator of check-point immunotherapy. As a useful diagnostic biomaterial, ExoDNA contains a variety of clinically relevant tumor-specific mutations representing multiple genes (e.g., EGFR, BRAF, RAS, IDH, and HER2), thus making it a promising “liquid biopsy” material for therapy recommendations. Hence, ExoDNA in addition to tumor immunity modulation, is also emerging as a suitable diagnostic material for personalized therapy in cancer. Here, we review the current status of ExoDNA research and its potential uses in tumor biology.     

American eels produce and release bile acid profiles that vary across life stage

The American eel (Anguilla rostrata) is an imperilled fish hypothesized to use conspecific cues, in part, to coordinate long-distance migration during their multistage life history. Here, holding water and tissue from multiple American eel life stages was collected and analysed for the presence, profile and concentration of bile acids. Distinct bile acid profiles were identified in glass, elver, yellow eel and silver eel holding waters using ultraperformance liquid chromatography high-resolution mass spectrometry and principal component analysis. Taurochenodeoxycholic acid, taurodeoxycholic acid, cholic acid, deoxycholic acid, taurolithocholic acid and taurocholic acid were detected in whole tissue of American glass eels and elvers, and in liver, intestine and gallbladder samples of late-stage yellow eels. Bile acids were not a major component of silver eel washings or tissue. This study is novel because little was previously known about bile acids produced and emitted into the environment by American eels. Future behavioural studies could evaluate whether any bile acids produced by American eels influence conspecific migratory behaviour.     

The evolution of floral nectaries in Disa (Orchidaceae: Disinae): recapitulation or diversifying innovation?

Background and Aims

The Orchidaceae have a history of recurring convergent evolution in floral function as nectar production has evolved repeatedly from an ancestral nectarless state. However, orchids exhibit considerable diversity in nectary type, position and morphology, indicating that this convergence arose from alternative adaptive solutions. Using the genus Disa, this study asks whether repeated evolution of floral nectaries involved recapitulation of the same nectary type or diversifying innovation. Epidermis morphology of closely related nectar-producing and nectarless species is also compared in order to identify histological changes that accompanied the gain or loss of nectar production.

Methods

The micromorphology of nectaries and positionally equivalent tissues in nectarless species was examined with light and scanning electron microscopy. This information was subjected to phylogenetic analyses to reconstruct nectary evolution and compare characteristics of nectar-producing and nectarless species.

Key Results

Two nectary types evolved in Disa. Nectar exudation by modified stomata in floral spurs evolved twice, whereas exudation by a secretory epidermis evolved six times in different perianth segments. The spur epidermis of nectarless species exhibited considerable micromorphological variation, including strongly textured surfaces and non-secreting stomata in some species. Epidermis morphology of nectar-producing species did not differ consistently from that of rewardless species at the magnifications used in this study, suggesting that transitions from rewardlessness to nectar production are not necessarily accompanied by visible morphological changes but only require sub-cellular modification.

Conclusions

Independent nectary evolution in Disa involved both repeated recapitulation of secretory epidermis, which is present in the sister genus Brownleea, and innovation of stomatal nectaries. These contrasting nectary types and positional diversity within types imply weak genetic, developmental or physiological constraints in ancestral, nectarless Disa. Such functional convergence generated by morphologically diverse solutions probably also underlies the extensive diversity of nectary types and positions in the Orchidaceae.     

Are there pollination syndromes in the Australian epacrids (Ericaceae: Styphelioideae)? A novel statistical method to identify key floral traits per syndrome

Background and Aims

Convergent floral traits hypothesized as attracting particular pollinators are known as pollination syndromes. Floral diversity suggests that the Australian epacrid flora may be adapted to pollinator type. Currently there are empirical data on the pollination systems for 87 species (approx. 15 % of Australian epacrids). This provides an opportunity to test for pollination syndromes and their important morphological traits in an iconic element of the Australian flora.

Methods

Data on epacrid–pollinator relationships were obtained from published literature and field observation. A multivariate approach was used to test whether epacrid floral attributes related to pollinator profiles. Statistical classification was then used to rank floral attributes according to their predictive value. Data sets excluding mixed pollination systems were used to test the predictive power of statistical classification to identify pollination models.

Key Results

Floral attributes are correlated with bird, fly and bee pollination. Using floral attributes identified as correlating with pollinator type, bird pollination is classified with 86 % accuracy, red flowers being the most important predictor. Fly and bee pollination are classified with 78 and 69 % accuracy, but have a lack of individually important floral predictors. Excluding mixed pollination systems improved the accuracy of the prediction of both bee and fly pollination systems.

Conclusions

Although most epacrids have generalized pollination systems, a correlation between bird pollination and red, long-tubed epacrids is found. Statistical classification highlights the relative importance of each floral attribute in relation to pollinator type and proves useful in classifying epacrids to bird, fly and bee pollination systems.     

The androgen receptor: a biologically relevant vaccine target for the treatment of prostate cancer

The androgen receptor (AR) plays an essential role in the development and progression of prostate cancer. However, while it has long been the primary molecular target of metastatic prostate cancer therapies, it has not been explored as an immunotherapeutic target. In particular, the AR ligand-binding domain (LBD) is a potentially attractive target, as it has an identical sequence among humans as well as among multiple species, providing a logical candidate for preclinical evaluation. In this report, we evaluated the immune and anti-tumor efficacy of a DNA vaccine targeting the AR LBD (pTVG-AR) in relevant rodent preclinical models. We found immunization of HHDII-DR1 mice, which express human HLA-A2 and HLA-DR1, with pTVG-AR augmented AR LBD HLA-A2-restricted peptide-specific, cytotoxic immune responses in vivo that could lyse human prostate cancer cells. Using an HLA-A2-expressing autochthonous model of prostate cancer, immunization with pTVG-AR augmented HLA-A2-restricted immune responses that could lyse syngeneic prostate tumor cells and led to a decrease in tumor burden and an increase in overall survival of tumor-bearing animals. Finally, immunization decreased prostate tumor growth in Copenhagen rats that was associated with a Th1-type immune response. These data show that the AR is as a prostate cancer immunological target antigen and that a DNA vaccine targeting the AR LBD is an attractive candidate for clinical evaluation.     

Fine scale movements and activity areas of white sharks (Carcharodon carcharias) in Mossel Bay, South Africa

Previous work on white sharks indicate the species show seasonally limited movement patters, at certain aggregation sites small areas may play vital roles in the life history of a large amount of the population. Acoustic telemetry was used to estimate habitat use of white sharks, Carcharodon carcharias, while aggregating at Mossel Bay, South Africa. Total range of all shark tracks combined accumulated 782 h and covered an area of 93.5 km² however, within this range, sharks were found to highly utilise a core habitat (50 % Kernel, K50) of just 1.05 km² over a reef system adjacent to a river mouth. Individual tracks revealed additional core habitats, some of which were previously undocumented and one adjacent to a commercial harbor. Much was found to be dependent on the size of the shark, with larger sharks (>400 cm) occupying smaller activity areas than subadult (300–399 cm) and juvenile (<300 cm) conspecifics, while Index of Reuse (IOR) and Index of Shared Space (IOSS) were both found to increase with shark size. Such results provide evidence that larger white sharks are more selective in habitat use, which indicates they have greater experience within aggregation sites. Furthermore, the focused nature of foraging means spatially restricted management strategies would offer a powerful tool to aid enforcement of current protective legislation for the white shark in similar environments of limited resources and capacity.     

Stable and radiogenic isotope analyses on shark teeth from the Early to the Middle Permian (Sakmarian–Roadian) of the southwestern USA

δ¹⁸O_P values and ⁸⁷Sr/⁸⁶Sr ratios were determined on disarticulated xenacanthiform, hybodontid and ctenacanthid shark tooth material from several Early Permian (Sakmarian–Kungurian) continental bone beds of northern Texas and southern Oklahoma as well as from the marine Middle Permian (Roadian) of northern Arizona. The δ¹⁸O_P values derived from the teeth of bone beds are in the range of 17.6–23.5‰ VSMOW, and are mostly depleted in ¹⁸O by 0.5–5‰ relative to proposed coeval marine δ¹⁸O_P values. This indicates an adaptation to freshwater habitats on the Early Permian coastal plain by several sharks. Distinctly higher δ¹⁸O_P values from two bone beds are attributed to significant evaporative enrichment in ¹⁸O in flood plain ponds. ⁸⁷Sr/⁸⁶Sr ratios of around 0.71077 are notably more radiogenic than ⁸⁷Sr/⁸⁶Sr of contemporaneous seawater. In contrast, the isotopic composition of teeth from the marine Kaibab Formation is characterised by low δ¹⁸O_P values in the range of 13.4–15.6‰ VSMOW while ⁸⁷Sr/⁸⁶Sr ratios of around 0.70821 are closer to the Roadian seawater value. The distinctly depleted δ¹⁸O_P values cannot be readily explained by fluvially affected freshening in a nearshore marine environment, so a diagenetic alteration of the Kaibab material seems to be more likely, excluding it from further interpretation.     

Attenuated PLD1 association and signalling at the H452Y polymorphic form of the 5-HT2A receptor

The 5-HT_2A receptor (5-HT_2AR) is implicated in psychotropic changes within the central nervous system (CNS). A number of polymorphisms have been reported in the 5-HT_2AR gene; one of these results in a non-synonymous change, H452Y, in the carboxy-terminal tail of the receptor protein. The minor allele (9% occurrence) has been statistically associated with CNS dysfunction such as impaired memory processing and resistance to neuroleptic treatment in schizophrenic patients. We investigated the impact of H452Y mutation of the 5-HT_2AR expressed in COS7 cells on distinctly coupled intracellular signalling pathways from the receptor, focusing on the heterotrimeric G protein-independent phospholipase D (PLD) pathway, compared to the conventional Gq/11-linked phospholipase C (PLC) pathway. The H452Y mutation selectively attenuated PLD signalling, which as in the wild-type receptor, was mediated by a molecular complex involving PLD1 docked to the receptor's carboxy-terminal tail domain. Co-immunoprecipitation and GST-fusion protein experiments revealed that the H452Y mutation selectively reduced PLD1 binding to the receptor. Experiments with blocking peptides to mimic short sections of the 5-HT_2AR tail sequence revealed that the peptide spanning residue 452 strongly reduced PLD but not PLC responses of the receptor. Similar observations were made when assessing both PLD responses and PLD-dependent cellular proliferation elicited by activation of 5-HT_2ARs natively expressed in MCF-7 cells. Overall these findings indicate that the H452Y polymorphic variant of the 5-HT_2AR displays selective disruption of its PLD signalling pathway. This may potentially play a role in the CNS dysfunction associated with the H452Y allele of the 5-HT_2AR.