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Nature Communications Jun 2024The extent of aerial flows of insects circulating around the planet and their impact on ecosystems and biogeography remain enigmatic because of methodological...
The extent of aerial flows of insects circulating around the planet and their impact on ecosystems and biogeography remain enigmatic because of methodological challenges. Here we report a transatlantic crossing by Vanessa cardui butterflies spanning at least 4200 km, from West Africa to South America (French Guiana) and lasting between 5 and 8 days. Even more, we infer a likely natal origin for these individuals in Western Europe, and the journey Europe-Africa-South America could expand to 7000 km or more. This discovery was possible through an integrative approach, including coastal field surveys, wind trajectory modelling, genomics, pollen metabarcoding, ecological niche modelling, and multi-isotope geolocation of natal origins. The overall journey, which was energetically feasible only if assisted by winds, is among the longest documented for individual insects, and potentially the first verified transatlantic crossing. Our findings suggest that we may be underestimating transoceanic dispersal in insects and highlight the importance of aerial highways connecting continents by trade winds.
Topics: Animals; Butterflies; Flight, Animal; Wind; Ecosystem; South America; Europe; Animal Migration; Pollen; Africa; Animal Distribution
PubMed: 38918383
DOI: 10.1038/s41467-024-49079-2 -
Plant Physiology Jun 2024Pollen germination and pollen tube elongation require rapid phospholipid production and remodeling in membrane systems that involve both de novo synthesis and turnover....
Pollen germination and pollen tube elongation require rapid phospholipid production and remodeling in membrane systems that involve both de novo synthesis and turnover. Phosphatidic acid phosphohydrolase (PAH) and lysophosphatidylcholine acyltransferase (LPCAT) are two key enzymes in membrane lipid maintenance. PAH generates diacylglycerol (DAG), a necessary precursor for the de novo synthesis of phosphatidylcholine (PC), while LPCAT reacylates lysophosphatidylcholine (LPC) to PC and plays an essential role in the remodeling of membrane lipids. In this study, we investigated the synthetic defects of pah and lpcat mutations in sexual reproduction of Arabidopsis (Arabidopsis thaliana) and explored the prospect of pistil lipid provision to pollen tube growth. The combined deficiencies of lpcat and pah led to decreased pollen tube growth in the pistil and reduced male transmission. Interestingly, pistils of the lipid mutant dgat1 ameliorated the male transmission deficiencies of pah lpcat pollen. In contrast, pollination with a non-specific phospholipase C (NPC) mutant exacerbated the fertilization impairment of the pah lpcat pollen. Given the importance of DAG in lipid metabolism and its contrasting changes in the dgat1 and npc mutants, we further investigated whether DAG supplement in synthetic media could influence pollen performance. DAG was incorporated into phospholipids of germinating pollen and stimulated pollen tube growth. Our study provides evidence that pistil derived lipids contribute to membrane lipid synthesis in pollen tube growth, a hitherto unknown role in synergistic pollen-pistil interactions.
PubMed: 38917229
DOI: 10.1093/plphys/kiae276 -
Annals of Botany Jun 2024Spatial variation in plant-pollinator interactions is a key driver of floral trait diversification. A so far overlooked qualitative aspect of this variation is the...
BACKGROUND AND AIMS
Spatial variation in plant-pollinator interactions is a key driver of floral trait diversification. A so far overlooked qualitative aspect of this variation is the behavioural component on flowers that relates to the pollinator fit. We tested the hypothesis that variation in pollinator behaviour influences the geographical pattern of phenotypic selection across the distribution range of the oil-producing Krameria grandiflora (Krameriaceae). This variation mainly involves the presence or absence of flag petal grasping, which is only performed by representatives of Centris (Centridini, Apidae), an oil-collecting bee group highly associated with Krameriaceae pollination.
METHODS
We quantified variation in floral traits and fitness and estimated pollinator-mediated selection in five populations at a large geographical scale comprising the entire species range. In each population, we sampled individual pollen arrival and germination as a fitness measure, indicating pollination success and pollination performance, which was then relativized and regressed on standardized flower-pollinator fit (flag-stigma distance), advertisement (sepal length) and reward (oil volume) traits. This generated mean-scaled selection gradients used to calculate geographical selection dispersion.
KEY RESULTS
Unexpectedly, stronger selection was detected on the flower-pollinator fit trait in populations highly associated to the absence of the flag petal grasping. Geographical variation in selection was mainly attributed to differential selection on the flag-stigma distance generating a selection mosaic. This may involve influences of a spatial variation in pollinator behaviour as well as composition and morphology.
CONCLUSIONS
Our results show the adaptive significance of the specialized "flag" petals of Krameria in the absence of the grasping behaviour and highlight the contribution of geographical variation in pollinator behaviour on flowers in driving selection mosaics, with implications for floral evolution, adaptation to pollinator fit and phenotypic diversity in specialized systems.
PubMed: 38916514
DOI: 10.1093/aob/mcae102 -
Journal of Computational Science... Mar 2024We have developed a series of course-based undergraduate research experiences for students integrated into course curriculum centered around the use of 3D visualization...
We have developed a series of course-based undergraduate research experiences for students integrated into course curriculum centered around the use of 3D visualization and virtual reality for science visualization. One project involves the creation and use of a volumetric renderer for hyperstack images, paired with a biology project in confocal microscopy. Students have worked to develop and test VR enabled tools for confocal microscopy visualization across headset based and CAVE based VR platforms. Two applications of the tool are presented: a rendering of primordial germ cells coupled with automated detection and counting, and a database in development of 3D renderings of pollen grains. Another project involves the development and testing of point cloud renderers. Student work has focused on performance testing and enhancement across a range of 2D and 3D hardware, including native Quest apps. Through the process of developing these tools, students are introduced to scientific visualization concepts, while gaining practical experience with programming, software engineering, graphics, shader programming, and cross-platform design.
PubMed: 38915788
DOI: 10.22369/issn.2153-4136/15/1/7 -
Plant Communications Jun 2024Transient heatwaves occur more frequently with climate warming, yet their impacts on crop yield are severely underestimated and even overlooked. Heatwaves spanning mere... (Review)
Review
Transient heatwaves occur more frequently with climate warming, yet their impacts on crop yield are severely underestimated and even overlooked. Heatwaves spanning mere days or even hours during sensitive stages (e.g., microgametogenesis and flowering) can significantly reduce crop yield by disrupting plant reproduction. Recently, advancements in multi-omics and GWAS analysis have shed light on specific organs (e.g., pollen, lodicule, and style), key metabolic pathways (sugar and reactive oxygen species (ROS) metabolisms, Ca homeostasis), and essential genes for transient heatwaves responses during the most sensitive stages in many crops. Based on this, this review places particular emphasis on the crop's heat-sensitive stages, using pollen development, floret opening, pollination, and fertilization as the central narrative thread. Complementing by key parts such as lodicule and tapetum, the multifaceted effects of transient heatwaves and their molecular basis are systematically demonstrated. A number of heat-tolerant genes for these processes have been identified in major crops such as maize and rice. The mechanisms and key heat-tolerant genes shared over different stages potentially facilitate the improvement of heat-tolerant crops more precisely.
PubMed: 38915200
DOI: 10.1016/j.xplc.2024.101009 -
Gene Jun 2024Products from stingless bees are rich reservoirs of microbial diversity, including yeasts with fermentative potential. Previously, two Saccharomyces cerevisiae strains,...
Products from stingless bees are rich reservoirs of microbial diversity, including yeasts with fermentative potential. Previously, two Saccharomyces cerevisiae strains, JP14 and IP9, were isolated from Jataí (Tetragonisca angustula) and Iraí (Nannotrigona testaceicornis) bees, respectively, aiming at mead production. Both strains presented great osmotic and sulfite tolerance, and ethanol production, although they have a high free amino nitrogen demand. Herein, their genomes were sequenced, assembled, and annotated, and the variants were compared to the S. cerevisiae S288c reference strain. The final assembly of IP9 and JP14 presented high N50 and BUSCO scores, and more than 6430 protein-coding genes. Additionally, nQuire predicted the ploidy of IP9 as diploid, but the results were not enough to determine the ploidy of JP14. The mitochondrial genomes of IP9 and JP14 presented the same gene content as S288c but the genes were rearranged and fragmentedin different patterns. Meanwhile, the genes with mutations of high impact (e.g., indels, gain of stop codon) for both yeasts were enriched for transmembrane transport, electron transfer, oxidoreductase, heme binding, fructose, mannose, and glucose transport, activities related to the respiratory chain and sugar metabolism. The IP9 strain presented copy number gains in genes related to sugar transport and cell morphogenesis; in JP14, genes were enriched for disaccharide metabolism and transport, response to reactive oxygen species, and polyamine transport. On the other hand, IP9 presented copy number losses related to disaccharide, thiamine, and aldehyde metabolism, while JP14 presented depletions related to disaccharide, oligosaccharide, asparagine, and aspartate metabolism. Notably, both strains presented a killer toxin gene, annotated from the assembling of unmapped reads, representing a potential mechanism for the control of other microorganisms population in the environment. Therefore, the annotated genomes of JP14 and IP9 presented a high selective pressure for sugar and nitrogen metabolism and stress response, consistent with their isolation source and fermentative properties.
PubMed: 38914244
DOI: 10.1016/j.gene.2024.148722 -
European Annals of Allergy and Clinical... Jun 2024Grass and olive pollens have overlapping pollination periods and are common allergens in the Iberian Peninsula. The objective is to determine the sensitization pattern...
Grass and olive pollens have overlapping pollination periods and are common allergens in the Iberian Peninsula. The objective is to determine the sensitization pattern to major Phleum pratense and Olea europaea pollens in the Portuguese population with pollen allergic rhinitis (AR) using molecular allergen diagnosis (MAD). Seasonal AR patients (≥ 12 years), with positive skin prick tests (SPT) to Phleum and Olea were recruited from 16 centers. Using ALEX2, specific IgE to Phl p1, Phl p2, Phl p5, Phl p6, Phl p7, Phl p 12, Ole e1, Ole e7 and Ole e9 were determined. Immunoblotting of Olea allergic patients was performed. Included 175 patients (55.4% female; mean age 31.6 ± 13.3 years; 85.7% adults; 40% asthmatic, Coast 28%/Inland 72% and North 29.1%/Centre 20.6%/South 50.3%). Considering Phleum MAD, 85.7% were sensitized to Phl p1, 45.7% to Phl p2, 50.3% to Phl p5, 45.7%, to Phl p6, 10.9% to Phl p7 and 22.9% to Phl p12. Sensitization to Ole e1 was found in 56.6%, to Ole e7 in 1.7% and Ole e9 in 3.4% patients. Sensitization to Phl p7 was more frequent in asthmatics (17.4% vs 6.6%; p = 0.044). Sensitization to Phl p5, Phl p6, Phl p12 and Ole e1 was more frequent in inland. Regarding sensitization patterns: 53.1% patients were sensitized to both species genuine´ sIgE, 38.3% to Phleum and 3.4% only to Olea species' sIgE. Immunoblotting of Olea allergic patients showed a high intensity band that may correspond to Ole e12. MAD showed "genuine" Grass and Olea sensitization in approximately 50% of our patients.
PubMed: 38913398
DOI: 10.23822/EurAnnACI.1764-1489.347 -
TAG. Theoretical and Applied Genetics.... Jun 2024The timely degradation of tapetum, the innermost somatic anther cell layer in flowering plants, is critical for pollen development. Although several genes involved in...
The timely degradation of tapetum, the innermost somatic anther cell layer in flowering plants, is critical for pollen development. Although several genes involved in tapetum development have been characterized, the molecular mechanisms underlying tapetum degeneration remain elusive. Here, we showed that mutation in Abnormal Degraded Tapetum 1 (ADT1) resulted in overaccumulation of Reactive Oxygen Species (ROS) and abnormal anther development, causing earlier tapetum Programmed Cell Death (PCD) and pollen abortion. ADT1 encodes a nuclear membrane localized protein, which is strongly expressed in the developing microspores and tapetal cells during early anther development. Moreover, ADT1 could interact with metallothionein MT2b, which was related to ROS scavenging and cell death regulation. These findings indicate that ADT1 is required for proper timing of tapetum PCD by regulating ROS homeostasis, expanding our understanding of the regulatory network of male reproductive development in rice.
Topics: Oryza; Pollen; Reactive Oxygen Species; Plant Proteins; Gene Expression Regulation, Plant; Mutation; Cell Death; Flowers; Apoptosis
PubMed: 38913206
DOI: 10.1007/s00122-024-04677-y -
Environmental Epidemiology... Dec 2023We aimed to assess whether the influence of urban vegetation on asthma development in children (<13 years) varies by type (e.g., total vegetation, tree type, and grass)...
OBJECTIVE
We aimed to assess whether the influence of urban vegetation on asthma development in children (<13 years) varies by type (e.g., total vegetation, tree type, and grass) and season.
METHODS
We used a cohort of all children born in Montreal, Canada, between 2000 and 2015. Children and cases were identified from linked medico-administrative databases. Exposure to residential vegetation was estimated using the Normalized Difference Vegetation Index (NDVI) for total vegetation and using the total area covered by deciduous and evergreen crowns for trees in 250 m buffers centered on residential postal codes. Seasonal variations in vegetation were modeled by setting values to zero on days outside of pollen and leaf-on seasons. Cox models with vegetation exposures, age as a time axis, and adjusted for sex, material deprivation, and health region were used to estimate hazard ratios (HR) for asthma development.
RESULTS
We followed 352,946 children for a total of 1,732,064 person-years and identified 30,816 incident cases of asthma. While annual vegetation (total and trees) measures did not appear to be associated with asthma development, models for pollen and leaf-on seasons yielded significant nonlinear associations. The risk of developing asthma was lower in children exposed to high levels (>33,300 m) of deciduous crown area for the leaf-on season (HR = 0.69; 95% confidence interval [CI] = 0.67, 0.72) and increased for the pollen season (HR = 1.07; 95% CI =1.02, 1.12), compared with unexposed children. Similar results were found with the Normalized Difference Vegetation Index.
CONCLUSION
The relationship between urban vegetation and childhood asthma development is nonlinear and influenced by vegetation characteristics, from protective during the leaf-on season to harmful during the pollen season.
PubMed: 38912389
DOI: 10.1097/EE9.0000000000000280 -
Applications in Plant Sciences 2024In this study, we use simulations to determine how pollen flow and sampling constraints can influence the genetic conservation found in seed collections.
PREMISE
In this study, we use simulations to determine how pollen flow and sampling constraints can influence the genetic conservation found in seed collections.
METHODS
We simulated genotypes of parental individuals and crossed the parentals based on three different ranges of pollen flow (panmictic, limited, and highly limited) to create new seed sets for sampling. We tested a variety of sampling scenarios modeled on those occurring in nature and calculated the proportion of alleles conserved in each scenario.
RESULTS
We found that pollen flow greatly influences collection outcomes, with panmictic pollen flow resulting in seed sets containing 21.6% more alleles than limited pollen flow and 48.6% more alleles than highly limited pollen flow, although this impact diminishes when large numbers of maternal plants are sampled. Simulations of realistic seed sampling (sampling more seed from some plants and fewer from others) showed a relatively minor impact (<2.5%) on genetic diversity conserved compared to ideal sampling (uniform sampling across all maternal plants).
DISCUSSION
We conclude that future work must consider limited pollen flow, but collectors can be flexible with their sampling in the field as long as many unique maternal plants are sampled. Simulations remain a fruitful method to advance ex situ sampling guidelines.
PubMed: 38912130
DOI: 10.1002/aps3.11561