LRRK2 kinase activity is necessary for development and regeneration in Nematostella vectensis.

BACKGROUND: The starlet sea anemone, Nematostella vectensis, is an emerging model organism with a high regenerative capacity, which was recently found to possess an orthologue to the human Leucine Rich Repeat Kinase 2 (LRRK2) gene. Mutations in this gene are the most common cause of inherited Parkinson's Disease (PD), highlighting the importance of understanding its function. Despite two decades of research, however, the function of LRRK2 is not well established. METHODS: To investigate the function of LRRKs in Nematostella vectensis, we applied small molecule inhibitors targeting the kinase activity of LRRK2 to examine its function in development, homeostasis and regeneration in Nematostella vectensis. RESULTS: In vivo analyses inhibiting the kinase function of this enzyme demonstrated a role of nvLRRK2 in development and regeneration of N. vectensis. These findings implicate a developmental role of LRRK2 in Nematostella, adding to the expanding knowledge of its physiological function. CONCLUSIONS: Our work introduces a new model organism with which to study LRRK biology. We report that LRRK kinase activity is necessary for the development and regeneration of Nematostella. Given the short generation time, genetic trackability and in vivo imaging capabilities, this work introduces Nematostella vectensis as a new model in which to study genes linked to neurodegenerative diseases such as Parkinson's.

LRRK2 kinase activity is necessary for development and regeneration in Nematostella vectensis.

Background: The starlet sea anemone, Nematostella vectensis, is an emerging model organism with a high regenerative capacity, which was recently found to possess an orthologue to the human LRRK2 gene (nvLRRK2). The leucine rich repeat kinase 2 (LRRK2) gene, when mutated, is the most common cause of inherited Parkinson's Disease (PD). Its protein product (LRRK2) has implications in a variety of cellular processes, however, the full function of LRRK2 is not well established. Current research is focusing on understanding the function of LRRK2, including both its physiological role as well as its pathobiological underpinnings. Methods: We used bioinformatics to determine the cross-species conservation of LRRK2, then applied drugs targeting the kinase activity of LRRK2 to examine its function in development, homeostasis and regeneration in Nematostella vectensis. Results: An in-silico characterization and phylogenetic analysis of nvLRRK2 comparing it to human LRRK2 highlighted key conserved motifs and residues. In vivo analyses inhibiting the kinase function of this enzyme demonstrated a role of nvLRRK2 in development and regeneration of N. vectensis. These findings implicate a developmental role of LRRK2 in Nematostella, adding to the expanding knowledge of its physiological function. Conclusions: Our work introduces a new model organism with which to study LRRK biology. We show a necessity for LRRK2 in development and regeneration. Given the short generation time, genetic trackability and in vivo imaging capabilities, this work introduces Nematostella vectensis as a new model in which to study genes linked to neurodegenerative diseases such as Parkinson's.

Examining the Relationship Between Existing Community Resources and Community Leaders' Perceptions of Resilience and Rural Health During COVID-19.

This study explored the relationship between existing community resources and community leaders' perceptions of resilience and rural health during COVID-19. Observational data of material capitals (e.g., grocery stores and physical activity resources) present in five rural communities involved in a health promotion project were collected and compared with key informant interviews of perceived community health and resilience during the COVID-19 pandemic. The analysis compares the differences in community leaders' perceptions of resilience during the pandemic to the actual material capitals of the community. While these rural counties were average in terms of available physical activity and nutritional resources, the onset of the pandemic led to varying degrees of disruption in access due to structural closures of mainstay resources, as well as residents perceiving that they cannot or should not access available resources. In addition, county coalition progress was stalled as individuals and groups could not gather together to complete projects, such as building playground equipment. This study demonstrates that existing quantitative instruments, such as NEMS and PARA, fail to take into account perceived access and utility of resources. Therefore, practitioners should consider multiple ways to evaluate resources, capacity, and progress on a health intervention or program and consider community voice to ensure feasibility, relevance, and sustainability-especially when faced with a public health emergency like COVID-19.

Community Gardens: A Catalyst for Community Change.

Community gardens are increasing in popularity and are associated with extensive physical and mental health benefits, increased access to fresh produce, and increased social connections. However, evidence is primarily from research in urban and school settings, and little is known about the role of community gardens in rural settings as part of policy, systems, and environmental (PSE) changes to promote health. This study explores the implementation of community gardens as part of an obesity prevention project, titled Healthier Together (HT), in five rural Georgia counties with limited food access and high obesity prevalence (>40%) using a mixed-methods research design that included data from project records, a community survey, interviews, and focus groups with county coalition members. Nineteen community gardens were implemented across five counties, 89% distributed produce direct to consumers, and 50% were integrated into the food system. Few (8.3%) of the survey respondents (n = 265) identified gardens as a food source, but 21.9% reported using an HT garden in the past year. Themes emerging from interviews (n = 39) and five focus groups suggested community gardens were a catalyst for broader community health change by increasing awareness of the value and absence of healthy food and generating excitement for future PSE initiatives to more comprehensively address food and physical activity access. Practitioners should consider placement of rural community gardens to optimize access to and distribution of produce as well as communication and marketing strategies to increase engagement and leverage gardens as gateways for PSE approaches to improve rural health.

A synthesis of deimatic behaviour.

Deimatic behaviours, also referred to as startle behaviours, are used against predators and rivals. Although many are spectacular, their proximate and ultimate causes remain unclear. In this review we aim to synthesise what is known about deimatic behaviour and identify knowledge gaps. We propose a working hypothesis for deimatic behaviour, and discuss the available evidence for the evolution, ontogeny, causation, and survival value of deimatic behaviour using Tinbergen's Four Questions as a framework. Our overarching aim is to direct future research by suggesting ways to address the most pressing questions in this field.

Testing the feasibility of the startle-first route to deimatism.

Many prey species perform deimatic displays that are thought to scare or startle would-be predators, or elicit other reflexive responses that lead to attacks being delayed or abandoned. The form of these displays differs among species, but often includes prey revealing previously-hidden conspicuous visual components. The evolutionary route(s) to deimatism are poorly understood, but it has recently been suggested that the behavioural component of the displays evolves first followed by a conspicuous visual component. This is known as the "startle-first hypothesis". Here we use an experimental system in which naïve domestic chicks forage for artificial deimatic prey to test the two key predictions of this hypothesis: (1) that movement can deter predators in the absence of conspicuously coloured display components; and, (2) that the combination of movement and conspicuously coloured display components is more effective than movement alone. We show that both these predictions hold, but only when the movement is fast. We thus provide evidence for the feasibility of 'the startle-first hypothesis' of the evolution of deimatism.

Eyespots.

Skelhorn et al. introduce eyespots the circular markings resembling vertebrate eyes found on many animals.