RESUMO
How do chemically defended animals resist their own toxins? This intriguing question on the concept of autotoxicity is at the heart of how species interactions evolve. In this issue of Molecular Ecology (Molecular Ecology, 2024, 33), Bodawatta and colleagues report on how Papua New Guinean birds coopted deadly neurotoxins to create lethal mantles that protect against predators and parasites. Combining chemical screening of the plumage of a diverse collection of passerine birds with genome sequencing, the researchers unlocked a deeper understanding of how some birds sequester deadly batrachotoxin (BTX) from their food without poisoning themselves. They identified that birds impervious to BTX bear amino acid substitutions in the toxin-binding site of the voltage-gated sodium channel Nav1.4, whose function is essential for proper contraction and relaxation of vertebrate muscles. Comparative genetic and molecular docking analyses show that several of the substitutions associated with insensitivity to BTX may have become prevalent among toxic birds through positive selection. Intriguingly, poison dart frogs that also co-opted BTX in their lethal mantles were found to harbour similar toxin insensitivity substitutions in their Nav1.4 channels. Taken together, this sets up a powerful model system for studying the mechanisms behind convergent molecular evolution and how it may drive biological diversity.
Assuntos
Animais Peçonhentos , Batraquiotoxinas , Aves Canoras , Animais , Batraquiotoxinas/genética , Neurotoxinas/toxicidade , Neurotoxinas/genética , Passeriformes/genética , Anuros/genética , Canal de Sódio Disparado por Voltagem NAV1.4/genética , Substituição de Aminoácidos , Rãs VenenosasRESUMO
Background: The Cultural Formulation Interview (CFI) is designed to improve understanding of patients' mental health care needs. The lack of empirical evidence on the impact and effectiveness of CFI use in clarifying people's perspectives, experiences, context, and identity, and in preventing cultural misunderstandings between migrant patients and clinicians, inspired this study. The objective is to examine the effect of the CFI on the strength of therapeutic working alliances, and the potential mediating or moderating role of perceived empathy. Materials and methods: A multicenter randomized controlled trial will be conducted, involving migrant patients, their confidants, and clinicians. The CFI will be administered in the intervention group, but not in the control group. Validated questionnaires will be used to assess therapeutic working alliances and perceived empathy. T-tests and linear regression analyses will be conducted to investigate between-group differences and possible mediating or moderating effects. Results: This study will indicate whether or not the CFI strengthens the therapeutic working alliance between patients and clinicians, as moderated and/or mediated by perceived empathy. Discussion: Research on the effect and impact of using the CFI in mental health care for migrant patients is important to clarify whether its use strengthens the therapeutic working alliance with clinicians. This can lead to a reduction in cultural misunderstandings and improve mental health care for migrant patients. The results may also be important for the implementation of the CFI as a standard of care. Ethics and dissemination: This research protocol was tailored to the needs of patients in collaboration with experts by experience. It was approved by the Ethical Review Board of the Tilburg Law School and registered in the Clinical Trials Register under number NCT05788315. Positive results may stimulate further implementation of the CFI in clinical practice, and contribute to improving the impact of the CFI on the therapeutic working alliances.
RESUMO
Populations can adapt to stressful environments through changes in gene expression. However, the role of gene regulation in mediating stress response and adaptation remains largely unexplored. Here, we use an integrative field dataset obtained from 780 plants of Oryza sativa ssp. indica (rice) grown in a field experiment under normal or moderate salt stress conditions to examine selection and evolution of gene expression variation under salinity stress conditions. We find that salinity stress induces increased selective pressure on gene expression. Further, we show that trans-eQTLs rather than cis-eQTLs are primarily associated with rice's gene expression under salinity stress, potentially via a few master-regulators. Importantly, and contrary to the expectations, we find that cis-trans reinforcement is more common than cis-trans compensation which may be reflective of rice diversification subsequent to domestication. We further identify genetic fixation as the likely mechanism underlying this compensation/reinforcement. Additionally, we show that cis- and trans-eQTLs are under different selection regimes, giving us insights into the evolutionary dynamics of gene expression variation. By examining genomic, transcriptomic, and phenotypic variation across a rice population, we gain insights into the molecular and genetic landscape underlying adaptive salinity stress responses, which is relevant for other crops and other stresses.