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Migration in animals and associated adaptations to contrasting environments are underpinned by complex genetic architecture. Here, we explore the genomic basis of facultative anadromy in brown trout (Salmo trutta), wherein some individuals migrate to sea while others remain resident in natal rivers, to better understand how alternative migratory tactics (AMTs) are maintained evolutionarily. To identify genomic variants associated with AMTs, we sequenced whole genomes for 194 individual trout from five anadromous-resident population pairs, situated above and below waterfalls, in five different Irish rivers. These waterfalls act as natural barriers to upstream migration and hence we predicted that loci underpinning AMTs should be under similar divergent selection across these replicate pairs. A sliding windows based analysis revealed a highly polygenic adaptive divergence between anadromous and resident populations, encompassing 329 differentiated genomic regions. These regions were associated with 292 genes involved in various processes crucial for AMTs, including energy homeostasis, reproduction, osmoregulation, immunity, circadian rhythm and neural function. Furthermore, examining patterns of diversity we were able to link specific genes and biological processes to putative AMT trait classes: migratory-propensity, migratory-lifestyle and residency. Importantly, AMT outlier regions possessed higher genetic diversity than the background genome, particularly in the anadromous group, suggesting balancing selection may play a role in maintaining genetic variation. Overall, the results from this study provide important insights into the genetic architecture of migration and the evolutionary mechanisms shaping genomic diversity within and across populations., (© 2024 The Author(s). Molecular Ecology published by John Wiley & Sons Ltd.)

Interspecific introgression is a potentially important source of novel variation of adaptive significance. Although multiple cases of adaptive introgression are well documented, broader generalizations about its targets and mechanisms are lacking. Multiallelic balancing selection, particularly when acting through rare allele advantage, is an evolutionary mechanism expected to favor adaptive introgression. This is because introgressed alleles are likely to confer an immediate selective advantage, facilitating their establishment in the recipient species even in the face of strong genomic barriers to introgression. Vertebrate major histocompatibility complex genes are well-established targets of long-term multiallelic balancing selection, so widespread adaptive major histocompatibility complex introgression is expected. Here, we evaluate this hypothesis using data from 29 hybrid zones formed by fish, amphibians, squamates, turtles, birds, and mammals at advanced stages of speciation. The key prediction of more extensive major histocompatibility complex introgression compared to genome-wide introgression was tested with three complementary statistical approaches. We found evidence for widespread adaptive introgression of major histocompatibility complex genes, providing a link between the process of adaptive introgression and an underlying mechanism. Our work identifies major histocompatibility complex introgression as a general mechanism by which species can acquire novel, and possibly regain previously lost, variation that may enhance defense against pathogens and increase adaptive potential., Competing Interests: Conflict of Interest The authors declare no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)

Background: Reproductive health promotion can enable early mitigation of behavioral and environmental risk factors associated with adverse pregnancy outcomes, while optimizing health of women + (all genders that can gestate a fetus) and babies. Although the biological and social influences of partners on pregnancy are well established, it is unknown whether online Canadian government reproductive health promotion also targets men and partners throughout the reproductive lifespan., Methods: Reproductive health promotion, designed for the general public, was assessed in a multi-jurisdictional sample of Canadian government (federal, provincial/territorial, and municipal) and select non-governmental organization (NGO) websites. For each website, information related to environmental and behavioral influences on reproductive health (preconception, pregnancy, postpartum) was evaluated based on comprehensiveness, audience-specificity, and scientific quality., Results: Government and NGO websites provided sparse reproductive health promotion for partners which was generally limited to preconception behavior topics with little coverage of environmental hazard topics. For women + , environmental and behavioral influences on reproductive health were well promoted for pregnancy, with content gaps for preconception and postpartum stages., Conclusion: Although it is well established that partners influence pregnancy outcomes and fetal/infant health, Canadian government website promotion of partner-specific environmental and behavioral risks was limited. Most websites across jurisdictions promoted behavioral influences on pregnancy, however gaps were apparent in the provision of health information related to environmental hazards. As all reproductive stages, including preconception and postpartum, may be susceptible to environmental and behavioral influences, online health promotion should use a sex- and gender-lens to address biological contributions to embryo, fetal and infant development, as well as contributions of partners to the physical and social environments of the home., (© 2024. The Author(s).)

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF. They are also intended to provide guidance to healthcare facilities seeking to establish or maintain catheter ablation for AF., (Copyright © 2024 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)