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Key Points A basic function of the Mediator complex is to communicate regulatory signals from DNA-binding transcription factors (TFs) directly to RNA polymerase II (Pol II). Different TFs, and the signalling pathways that regulate these TFs, often interact with different Mediator subunits to regulate expression of their target genes. Mediator is composed of a large number of subunits, some of which can reversibly associate with Mediator or are expressed at variable levels in different cell types. Mediator binding to various proteins and protein complexes, such as TFs, Pol II and the cyclin-dependent kinase 8 (CDK8) module, results in large-scale structural changes. These structural changes, in turn, appear to modulate the function of Mediator and may affect its ability to bind to other proteins. Because of its direct and extensive interactions with Pol II, Mediator regulates multiple stages of Pol II transcription (for example, initiation and re-initiation). Mediator interactions with the super elongation complex (SEC) also seem to be important for its regulation of Pol II elongation. The interactions between TFs, Mediator, cohesin and the pre-initiation complex (PIC) correlate with the formation of enhancer–promoter DNA loops, which are an important regulatory mechanism. Interactions between Mediator and non-coding RNA also correlate with DNA looping. RNA polymerase II (Pol II) is globally regulated by Mediator, a large, conformationally flexible protein complex with a variable subunit composition. These biochemical characteristics are fundamental for the ability of Mediator to control processes involved in transcription, including the organization of chromatin architecture and the regulation of Pol II pre-initiation, initiation, re-initiation, pausing and elongation. The RNA polymerase II (Pol II) enzyme transcribes all protein-coding and most non-coding RNA genes and is globally regulated by Mediator — a large, conformationally flexible protein complex with a variable subunit composition (for example, a four-subunit cyclin-dependent kinase 8 module can reversibly associate with it). These biochemical characteristics are fundamentally important for Mediator's ability to control various processes that are important for transcription, including the organization of chromatin architecture and the regulation of Pol II pre-initiation, initiation, re-initiation, pausing and elongation. Although Mediator exists in all eukaryotes, a variety of Mediator functions seem to be specific to metazoans, which is indicative of more diverse regulatory requirements.

Removal or loss of top-predators has been predicted to cause cascading negative effects for ecosystems, including mesopredator release. However, reliable evidence for these processes in terrestrial systems has been mixed and equivocal due, in large part, to the systemic and continued use of low-inference study designs to investigate this issue. Even previous large-scale manipulative experiments of strong inferential value have been limited by experimental design features (i.e. failure to prevent migration between treatments) that constrain possible inferences about the presence or absence of mesopredator release effects. Here, we build on these previous strong-inference experiments and report the outcomes of additional large-scale manipulative experiments to eradicate Australian dingoes from two fenced areas where dingo migration was restricted and where theory would predict an increase in extant European red foxes, feral cats and goannas. We demonstrate the removal and suppression of dingoes to undetectable levels over 4–5 years with no corresponding increases in mesopredator relative abundances, which remained low and stable throughout the experiment at both sites. We further demonstrate widespread absence of negative relationships between predators, indicating that the mechanism underpinning predicted mesopredator releases was not present. Our results are consistent with all previous large-scale manipulative experiments and long-term mensurative studies which collectively demonstrate that (1) dingoes do not suppress red foxes, feral cats or goannas at the population level, (2) repeated, temporary suppression of dingoes in open systems does not create mesopredator release effects, and (3) removal and sustained suppression of dingoes to undetectable levels in closed systems does not create mesopredator release effects either. Our experiments add to similar reports from North America, Asia, Europe and southern Africa which indicate that not only is there a widespread absence of reliable evidence for these processes, but there is also a large and continually growing body of experimental evidence of absence for these processes in many terrestrial systems. We conclude that although sympatric predators may interact negatively with each other on smaller spatiotemporal scales, that these negative interactions do not always scale-up to the population level, nor are they always strong enough to create mesopredator suppression or release effects.

Rapidly changing climate is likely to modify the spatial distribution of both flora and fauna. Land use change continues to alter the availability and quality of habitat and further intensifies the effects of climate change on wildlife species. We used an ensemble modeling approach to predict changes in habitat suitability for an iconic wildlife species, greater one‐horned rhinoceros due to the combined effects of climate and land use changes. We compiled an extensive database on current rhinoceros distribution and selected nine ecologically meaningful environmental variables for developing ensemble models of habitat suitability using ten different species distribution modeling algorithms in the BIOMOD2 R package; and we did this under current climatic conditions and then projected them onto two possible climate change scenarios (SSP1‐2.6 and SSP5‐8.5) and two different time frames (2050 and 2070). Out of ten algorithms, random forest performed the best, and five environmental variables—distance from grasslands, mean temperature of driest quarter, distance from wetlands, annual precipitation, and slope, contributed the most in the model. The ensemble model estimated the current suitable habitat of rhinoceros to be 2610 km2, about 1.77% of the total area of Nepal. The future habitat suitability under the lowest and highest emission scenarios was estimated to be: (1) 2325 and 1904 km2 in 2050; and (2) 2287 and 1686 km2 in 2070, respectively. Our results suggest that over one‐third of the current rhinoceros habitat would become unsuitable within a period of 50 years, with the predicted declines being influenced to a greater degree by climatic changes than land use changes. We have recommended several measures to moderate these impacts, including relocation of the proposed Nijgad International Airport given that a considerable portion of potential rhinoceros habitat will be lost if the airport is constructed on the currently proposed site. We developed ensemble models to predict the changes in suitable habitats for rhinoceros in Nepal. We estimated that about 1.77% of the total area of Nepal is currently suitable for rhinoceros. Our results indicate that over one‐third of the current rhinoceros habitat would become unsuitable within a period of 50 years.

Ethical food choices have become an important societal theme in post-industrial countries. Many consumers are particularly interested in the animal welfare implications of the various foods they may choose to consume. However, concepts in animal welfare are rapidly evolving towards consideration of all animals (including wildlife) in contemporary approaches such as “One Welfare”. This approach requires recognition that negative impacts (harms) may be intentional and obvious (e.g., slaughter of livestock) but also include the under-appreciated indirect or unintentional harms that often impact wildlife (e.g., land clearing). This is especially true in the Anthropocene, where impacts on non-human life are almost ubiquitous across all human activities. We applied the “harms” model of animal welfare assessment to several common food production systems and provide a framework for assessing the breadth (not intensity) of harms imposed. We considered all harms caused to wild as well as domestic animals, both direct effects and indirect effects. We described 21 forms of harm and considered how they applied to 16 forms of food production. Our analysis suggests that all food production systems harm animals to some degree and that the majority of these harms affect wildlife, not livestock. We conclude that the food production systems likely to impose the greatest overall breadth of harms to animals are intensive animal agriculture industries (e.g., dairy) that rely on a secondary food production system (e.g., cropping), while harvesting of locally available wild plants, mushrooms or seaweed is likely to impose the least harms. We present this conceptual analysis as a resource for those who want to begin considering the complex animal welfare trade-offs involved in their food choices.

For homeostasis, lingual taste papilla organs require regulation of epithelial cell survival and renewal, with sustained innervation and stromal interactions. To investigate a role for Hedgehog/GLI signaling in adult taste organs we used a panel of conditional mouse models to manipulate GLI activity within epithelial cells of the fungiform and circumvallate papillae. Hedgehog signaling suppression rapidly led to taste bud loss, papilla disruption, and decreased proliferation in domains of papilla epithelium that contribute to taste cells. Hedgehog responding cells were eliminated from the epithelium but retained in the papilla stromal core. Despite papilla disruption and loss of taste buds that are a major source of Hedgehog ligand, innervation to taste papillae was maintained, and not misdirected, even after prolonged GLI blockade. Further, vimentin-positive fibroblasts remained in the papilla core. However, retained innervation and stromal cells were not sufficient to maintain taste bud cells in the context of compromised epithelial Hedgehog signaling. Importantly taste organ disruption after GLI blockade was reversible in papillae that retained some taste bud cell remnants where reactivation of Hedgehog signaling led to regeneration of papilla epithelium and taste buds. Therefore, taste bud progenitors were either retained during epithelial GLI blockade or readily repopulated during recovery, and were poised to regenerate taste buds once Hedgehog signaling was restored, with innervation and papilla connective tissue elements in place. Our data argue that Hedgehog signaling is essential for adult tongue tissue maintenance and that taste papilla epithelial cells represent the key targets for physiologic Hedgehog-dependent regulation of taste organ homeostasis. Because disruption of GLI transcriptional activity in taste papilla epithelium is sufficient to drive taste organ loss, similar to pharmacologic Hedgehog pathway inhibition, the findings suggest that taste alterations in cancer patients using systemic Hedgehog pathway inhibitors result principally from interruption of signaling activity in taste papillae.

Threatened species throughout the world are in decline due to various causes. In some cases, predators of conservation or cultural value are causing the decline of threatened prey, presenting a conservation conundrum for managers. We surveyed marine turtle nests on K'gari (formally known as Fraser Island), Australia, to investigate dingo predation of green and loggerhead turtle nests, where each of these species is of conservation value. Our monitoring revealed that 84% of nests were predated by dingoes. Only 16% of nests were not consumed by dingoes, and only 5.7% of nests were confirmed to have successfully hatched. Up to 94% of nests were consumed in some areas, and predation rates were similar across different dingo packs. Information on the available numbers of nests and dingoes in the area indicated that turtle nests alone are sufficient to support extant dingoes over the summer. These results indicate that marine turtle eggs represent a previously unquantified but important food source for dingoes on K'gari, and that turtle nests at this rookery site are under serious threat from dingoes. This research should highlight the importance of prioritising the protection of turtle nests from dingoes or risk losing the entire rookery forever in the near future. Dingo versus turtles: a management conundrum when species of conservation and cultural significance collide on a World Heritage‐listed island. Implications for conserving both species and the viability of a marine turtle rookery.

The identification and implementation of conflict reduction measures are necessary to reduce predator attacks on people and livestock and to minimize human encroachment into predator habitats. We identified potential human–tiger conflict reduction measures and prioritized these measures for Chitwan National Park, Nepal. We identified these measures through a literature review, key informant interviews and a local stakeholder workshop. We prioritized the identified measures using a questionnaire survey of victims of tiger attacks (farmers, forest users and fishers), beneficiaries of tiger conservation (tourist guides, Jeep and elephant safari operators, tour and hotel operators and business operators) and National Park managers. We identified 22 measures (12 preventative, five reactive and five mitigative) as having potential for reducing negative interactions between people and tigers. Amongst these, we identified compensation payments, tiger-proof fences and habitat and prey management as high-priority measures. Conflict reduction priorities also varied amongst stakeholder groups. The victims assigned the highest priority to the construction of tiger-proof fences, whereas beneficiaries identified the management of habitat and prey as their highest priority. Compensation payments were the first preference of National Park managers and were amongst the top two priorities of all stakeholder groups. We recommend the adoption of the identified stakeholder priorities for reducing human–tiger conflict around Chitwan National Park and encourage consideration of the variations in priorities between stakeholder groups during policy development and decision-making.

Tigers (Panthera tigris) are apex predators and vital indicators of a healthy terrestrial ecosystem. Their effective conservation demands long-term data on their populations, prey abundance, and anthropogenic disturbances from humans and domestic animals across different forest management regimes. In this study, we analyzed camera trap datasets (2009, 2013, 2018, and 2022) from Parsa National Park, its buffer zone, and adjoining national forests. Using the Relative Abundance Index (RAI), we quantified the abundance of tigers, prey, humans, and domestic animals. Our findings revealed a significant increase (χ2 = 9.6; df = 3; p < 0.05) in the RAI of tigers (from 2.65 in 2009 to 7.11 in 2022) and their prey, coupled with a decrease in anthropogenic disturbances in the national park. Meanwhile, no significant differences in the RAI of tigers and their prey were observed in the buffer zone and national forests. We also found an increasing trend of human disturbances (RAI from 351.44 in 2009 to 389.7 in 2022) in the national forests. However, the abundance of domestic animals showed a decreasing trend across all three forest management regimes. Our results suggest that a reduction in anthropogenic disturbances has a more notable positive impact on tigers’ abundance than on their prey. This study emphasizes the need for directed conservation policies to reduce anthropogenic disturbances in buffer zones and national forests, while also addressing local needs and securing their goodwill for sustainable tiger conservation.

Humans and dingoes (Canis familiaris (dingo)) share the environment of K’gari, and conflict inevitably occurs between the two species, particularly over food. Dingo attacks on humans have occurred, and some have been serious and even fatal in outcome. Wildlife feeding may cause animals to develop unnatural and potentially dangerous behaviours towards conspecifics and humans on a relatively frequent basis. Food-based attraction has been implicated in the development of human-directed aggression in the dingo population of K’gari. Supplemental feeding, whether intentional or accidental, alters wildlife foraging behaviours and may have consequences at the population and ecosystem levels. Management strategies such as education programs, prohibition of inappropriate human behaviours (compliance) and fencing of garbage dumps have each been implemented to stop the intentional or inadvertent feeding of dingoes by people. However, there has been no formal assessment of the effectiveness of these interventions at reducing food-related dingo–human incidents over time. We collated and analysed 7791 unique reports of dingo–human interactions on K’gari between 1990 and 2020, inclusive of 1307 food-related reports, including the severity of these interactions. These data showed clear seasonal peaks in the percentage of food-related dingo–human interactions, corresponding with biologically significant breeding periods in autumn and weaning and dispersing in spring. Trends in serious food-related incidents remained stable overtime. Less serious food-related incidents declined, suggesting that management efforts were successful. However, these efforts appear to have reached the limits of their effectiveness. Further innovations are required to reduce serious incidents involving the relatively few dingoes and people still experiencing conflict, and thereby provide protection to both species on K’gari.

Environmental DNA (eDNA) has transformed biodiversity monitoring, especially in aquatic environments; yet, its application in terrestrial habitats remains limited. In arid regions, artificial waterbodies, such as farm dams and water troughs, serve as essential resources for wildlife and offer a promising but underutilised opportunity for eDNA‐based detection. Here, we designed and validated a highly sensitive, species‐specific quantitative PCR (qPCR) assay to detect the nationally threatened southern squatter pigeon (Geophaps scripta scripta). We validated the qPCR assay in the field by successfully detecting the target species at extremely low DNA concentrations (1 × 10−7 ng/μL; r2 = 0.992) using both active syringe and passive filtration methods across multiple farm dams and water troughs on a 20,000‐ha cattle property in northern Australia. To complement eDNA analysis, we also undertook standardised 20‐min, 2‐ha bird surveys at these sites. Positive detections were recorded at both trough and dam sites during the austral tropical dry season. Notably, whilst eDNA detections and visual bird counts aligned in terms of the number of occupied sites, their exact locations did not always coincide, highlighting the complementary nature of these two monitoring techniques. This assay represents a significant advancement in the conservation of this threatened ground‐nesting species, demonstrating that eDNA sampling at artificial waterpoints is a viable tool for monitoring terrestrial fauna in remote, semi‐arid landscapes.