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Sperm DNA methylation landscape and its links to male fertility in a non-model teleost using EM-seq
Get PDFDifferential DNA methylation due to epigenetic phenomena is crucial in regulating gene expression. Understanding the consequences of such differential expression on sperm quality parameters may provide insights into the underlying mechanisms of male reproductive success. Nonetheless, male fertility in fish remains understudied despite its critical importance to overall reproductive success in nature and captivity. This study investigated the DNA methylation landscape in spermatozoa of domesticated Arctic charr (Salvelinus alpinus) and its associations with sperm quality parameters. Computer assisted-semen analysis (CASA) was performed in 47 sperm samples of farmed Arctic charr, followed by enzymatic methylation sequencing (EM-seq). Our results showed that the DNA of Arctic charr sperm is highly methylated (mean value of similar to 86%), though variations were observed in genomic features involved in gene regulation. Methylation at variable CpG sites exhibited regional correlation decaying by physical distance, while methylation similarities among individuals were strongly coupled with genetic variation and mirrored pedigree structure. Comethylation network analyses for promoters, CpG islands and first introns revealed genomic modules significantly correlated with sperm quality traits (p < 0.05; Bonferroni adjusted), with distinct patterns suggesting a resource trade-off between sperm concentration and kinematics. Furthermore, annotation and gene-set enrichment analysis highlighted biological mechanisms related to spermatogenesis, cytoskeletal regulation, and mitochondrial function, all vital to sperm physiology. These findings suggest that DNA methylation is a critical and fundamental factor influencing male fertility in Arctic charr, providing insights into the underlying mechanisms of male reproductive success
Unravelling theory in choice analysis: do consumers fill in the blanks?
Get PDFUnravelling theory postulates that consumers assume products without quality information are of the lowest quality. In a discrete choice experiment (DCE) with 1987 respondents from the UK, we find evidence against this assumption. Affirmative disclosure, which indicates only quality above the lowest level, lowers marginal utilities compared to complete disclosure. The development in food choice DCE studies, from textual and complete towards visual and affirmative increases mean willingness to pay and error variance. This suggests that analysts should carefully consider how attributes are presented when designing DCEs to avoid biased welfare estimates, especially when aiming for accurate market predictions or policy advice
A trait spectrum linking nitrogen acquisition and carbon use of ectomycorrhizal fungi
Get PDFTrait spectra have been used in various branches of ecology to explain and predict patterns of species distributions. Several categorical and continuous traits have been proposed as relevant for ectomycorrhizal fungi, but a spectrum that unifies co-varying traits remains to be established and tested. Here, we propose a nitrogen acquisition and carbon use trait spectrum for ectomycorrhizal fungi in nitrogen-limited forests, which encompasses several morphological, physiological, and metabolic traits. Using a simple stoichiometric model, the trait spectrum is linked to the concept of apparent carbon use efficiency and resolves the contradiction that species with high supply of host carbon can maintain nitrogen transfer despite building large mycelial biomass. We suggest that ectomycorrhizal fungal species are distributed along this spectrum, with lifestyles ranging from 'absorbers' with a niche in high productive forests with high availability of soluble nitrogen to 'miners' with the ability to exploit organic matter in forests with low nitrogen availability. Further, we propose ways to test the outlined trait spectrum empirically
Inoculation with in vitro promising plant growth-promoting bacteria isolated from nitrogen-limited boreal forest did not translate to in vivo growth promotion of agricultural plants
Get PDFMany yet undiscovered plant growth-promoting bacteria are proposed to be harboured in the nitrogen-limited boreal forest. These bacteria are suggested to increase plant growth not only due to their ability to fix nitrogen but also through other growth-promoting properties. Therefore, this study looked at the plant growth promotion potential of endophytic bacteria isolated from boreal forest conifer Scots pine (Pinus sylvestris) needles. Seven assays were used to measure the potential plant growth-promoting abilities of two newly isolated bacteria in this study and seven additionally selected bacteria isolated in our previous study. The three best-performing bacteria were used, either individually or in a consortium, to assess growth promotion on four common crop species. The greenhouse study included the presence of native soil and seed microbiota and used naturally nutrient-abundant soil. The results showed that while all bacteria were capable of multiple plant growth-promoting properties in the in vitro assays, they did not promote plant growth in the in vivo experiment as inoculated plants had similar or decreased chlorophyll content, root and shoot length and dry biomass compared to control plants. Our results show that bacterial plant growth-promoting potential does not always translate into successful plant growth increase in in vivo conditions and highlight the need for a better understanding of plant-bacteria interaction for the future establishment of successful bacterial bioinoculants
Identifying strategies to manage boreal forests: simulating moose and timber management scenarios at a landscape scale in the face of changing environmental conditions
Get PDFThere are ongoing debates among different stakeholders about which forest and ungulate management strategies will sustain high levels of timber and animal harvest and maintain important ecosystem functions under climate change. Ungulate-forest interactions are complex, including periods where forest regeneration is sensitive to browsing pressure, making it difficult to predict the consequences of a given strategy over time. To aid decision-making, we simulated the impacts of moose browsing on forest succession under 18 different combinations of moose (Alces alces) harvest rate levels and forest management scenarios in a boreal forest landscape in southern Sweden given projected changes in forest growth due to climate change. We found that the current management practices are important for sustaining a moose-forest system. Increasing moose harvest rates led to slightly smaller moose populations, larger estimates of landscape carrying capacity, and less biomass removal of Scots pine (Pinus sylvestris), a commercially valuable species. However, minor changes in the moose harvest were hardly affecting timber production. Increasing the timber harvest rotation time led to the highest estimates of Scots pine biomass, while thinning younger cohorts lead to the highest estimates of Norway spruce (Picea abies) biomass. These changes came without much effect to moose population dynamics. However, the increased broadleaf production scenario had a very large positive effect on total aboveground live biomass of deciduous species and on landscape carrying capacity and moose density. This scenario subsequently resulted in the greatest estimates of biomass removal of Scots pine, highlighting the tradeoffs associated with increased moose production
Effects of insecticide treatment against blue stem weevil (Ceutorhynchus sulcicollis) and cabbage stem weevil (C. pallidactylus) on crop injury and yield in winter oilseed rape (Brassica napus)
Get PDFBlue stem weevil (Ceutorhynchus sulcicollis) and cabbage stem weevil (C. pallidactylus) can occur in high numbers in winter oilseed rape (Brassica napus) fields in Sweden, but their impact on crop yield is poorly known, hindering the development of evidence-based pest management recommendations. We conducted five field experiments in two cropping seasons, where we tested pyrethroid insecticide application in autumn targeting C. sulcicollis, in spring targeting C. pallidactylus, as well as combined applications in autumn and spring targeting both species. We evaluated stem injury, emergence of the new generation of weevils and crop yield and oil content. Insecticide treatment in autumn reduced stem injury length and severity by C. sulcicollis, whereas insecticide treatment in spring did not affect stem injury. Emergence of the two species was similar across all treatments, which possibly was an artefact of limited sampling effort and small-scale spatial heterogeneity in emergence. Insecticide treatment in autumn, spring or a combined treatment all increased yield by 8-10 % (185-245 kg ha(-1)) with minor effects on oil content. Our results show that C. sulcicollis cause significant yield loss that can be reduced by insecticide treatment in autumn, which therefore can be economically motivated, whereas the results for insecticide treatment in spring targeting C. pallidactylus are inconclusive. Stem mining weevils are just some of several insect pests that can be economically important in oilseed rape and the availability of insecticides is declining. This calls for research into preventative pest management and well-motivated use of the few insecticides that remain in use
Urban greenspace to support social integration of immigrants? Case studies across Sweden
Get PDFThe successful integration of immigrants into European societies has become a crucial policy issue in the past decade. Urban greenspace (UGS) provides social spaces for people with different ethnic backgrounds; however, the relationships between the social integration of immigrants with the reciving society and UGS have attracted relatively little research interest. This study aims to explore the role of UGS in enhancing the social integration of first-generation immigrants in Sweden ("new-Swedes") by focusing on four forms of social integration: structural, interactive, cultural, and identificational. We draw on a sample of 280 interviews with new-Swedes from nine urban settlements in Sweden. Our results show that UGS in Sweden provides multiple opportunities for interactive integration among people from diverse cultures, including the receiving society, and that the accessibility, quality, and availability of UGS are crucial for structural integration. Although UGS do not primarily serve as venues for developing new relationships between new and native Swedes, they do facilitate social interactions within families and cultural communities. Additionally, UGS expose new Swedes to Swedish cultural norms regarding outdoor recreation. Our findings underscore the importance of critical infrastructure in promoting social interaction and integration. Active roles of immigrants in UGS planning and management will ensure that their needs and interests are considered in UGS design and offer important opportunities to be better connected to the receiving society. Finally, understanding the potential contribution of UGS also requires understanding the extent and depth of such integration
Warmer Lakes Support Phytoplankton Over Fish
Get PDFClimate warming reshapes biomass distributions across trophic levels in aquatic systems, with implications for ecosystem functioning and service provisioning. Using a space-for-time approach across temperate and boreal lakes, we analyse a dataset spanning wide gradients in temperature and nutrient availability, including species and biomass data for phytoplankton, fish, and, in some cases, zooplankton. We hypothesise that (1) warmer lakes have higher fish-to-phytoplankton biomass ratios than colder lakes, and (2) this relationship weakens at high phosphorus levels due to proliferation of inedible phytoplankton. Contrary to expectations, our results show that warmer lakes exhibit lower fish-to-phytoplankton biomass ratios, regardless of phosphorus concentrations or the contribution of benthic relative to whole lake primary production. This suggests reduced energy transfer efficiency from producers to consumers in warming waters. Changes in phytoplankton and fish community composition are likely part of the explanation for why increased phytoplankton biomass in warmer lakes does not translate into higher fish biomass. Our findings highlight a critical shift in biomass distribution from fish to phytoplankton with rising temperatures in northern lakes, potentially signalling future declines in food web efficiency and predator biomass under continued climate warming
Multi-Decadal Trends in Northern Lakes Show Contrasting Responses of Phytoplankton and Benthic Macroinvertebrates to Climate Change
Get PDFThree decades of continuous monitoring of 110 lakes across Sweden revealed significant long-term changes in physicochemical habitat and biological assemblages comprising multiple trophic levels related to climate. Mean annual air temperature increased for almost all lakes, with notable increases in the northern region. The environmental variables that showed the strongest temporal patterns were increasing water temperatures and decreasing nutrient (TP) and TOC concentrations for lakes in the north and increasing pH and TOC for lakes in the south. As hypothesized, phytoplankton and benthic macroinvertebrate (littoral and profundal) assemblages tracked climate changes directly (temperature, precipitation) and indirectly (changes in physicochemical habitat), but trends differed among the organism groups. The most pronounced changes in both magnitudes and rates of change (slopes) of the biological trends were found in the northernmost ecoregions. In these nutrient- and species-poor ecosystems, taxon richness and diversity had contrasting patterns: phytoplankton and profundal macroinvertebrates had negative slopes while littoral macroinvertebrates had positive slopes. Total phytoplankton biovolume and littoral macroinvertebrate abundance had positive slopes. Spatiotemporal patterns of phytoplankton and littoral macroinvertebrates were largely correlated with temperature and nutrients but not profundal assemblages. For lakes in the south isolating climate-induced effects was confounded by post-acidification recovery, for example, all three organism groups correlated with pH but not with water temperature. Combined results from all of the study lakes indicated habitat-specific responses of biological assemblages to long-term changes in climate and physicochemical habitat. Climate change coupled with catchment vegetation and post-acidification recovery pose heterogeneous impacts directly (temperature) and indirectly (physicochemical habitat) on lake assemblages. All three organism groups showed trends related to climate and therefore should be considered robust sentinels to gauge climate impacts directly and trophic-level effects indirectly in these climate-vulnerable ecosystems
A critical review on the welfare of Japanese quail in cage-free housing: Current knowledge and future perspectives
Get PDFThe Japanese quail (Coturnix japonica) is an increasingly popular species in poultry production. Concern about poultry welfare, including quail, has resulted in a stronger focus for farms to transition to cage-free housing as highlighted by the 2020 European Citizens' Initiative 'End the Cage Age'. Knowledge about how to design cagefree housing to accommodate Japanese quail's behavioral and physiological needs is scarce, and there are currently no standardized regulations regarding this type of housing for quail in the EU. Based on available literature, we review current information on the specific needs and requirements of quail to facilitate the transition to cage-free systems. Overall, the literature shows that Japanese quail spend most of their time on the ground, often pecking, scratching, or hiding under cover, that they will lay eggs in nests if these are provided and appropriately designed, and that they dustbathe if given substrate to do so. However, information about optimal group size, stocking density, nest design, and appropriate litter substrates have not been sufficiently well researched in non-cage systems, and neither has the design of cage-free housing when large groups of quail are housed together. Additionally, guidelines regarding successful management of the reportedly high level of agonistic behavior performed by male quail housed in groups is missing, as well as instructions on the ideal sex ratio in large breeding flocks. In addition to controlled experimental studies to fill specific knowledge gaps in these areas, we suggest precision livestock farming technologies such as real-time image analysis and modelling using artificial intelligence to gather this information on farms and/or in research studies. We also suggest using genomic selection to tackle the high levels of agonistic behavior reported in male Japanese quail by identifying the genetic architecture underlying this trait to facilitate faster selection against it. While phasing out caged housing for Japanese quail has been suggested to ensure better animal welfare, this review highlights that more information and research are needed to guarantee that this transition doesn't introduce new welfare and general managing problems in quail. We suggest that knowledge and experience about this transition from other poultry species, especially laying hens, can be used to facilitate the transition