-
BMC Plant Biology Jun 2024During male gametogenesis of flowering plants, sperm cell lineage (microspores, generative cells, and sperm cells) differentiated from somatic cells and acquired...
BACKGROUND
During male gametogenesis of flowering plants, sperm cell lineage (microspores, generative cells, and sperm cells) differentiated from somatic cells and acquired different cell fates. Trimethylation of histone H3 on lysine 4 (H3K4me3) epigenetically contributes to this process, however, it remained unclear how H3K4me3 influences the gene expression in each cell type. Here, we conducted chromatin immunoprecipitation sequencing (ChIP-seq) to obtain a genome-wide landscape of H3K4me3 during sperm cell lineage development in tomato (Solanum lycopersicum).
RESULTS
We show that H3K4me3 peaks were mainly enriched in the promoter regions, and intergenic H3K4me3 peaks expanded as sperm cell lineage differentiated from somatic cells. H3K4me3 was generally positively associated with transcript abundance and served as a better indicator of gene expression in somatic and vegetative cells, compared to sperm cell lineage. H3K4me3 was mutually exclusive with DNA methylation at 3' proximal of the transcription start sites. The microspore maintained the H3K4me3 features of somatic cells, while generative cells and sperm cells shared an almost identical H3K4me3 pattern which differed from that of the vegetative cell. After microspore division, significant loss of H3K4me3 in genes related to brassinosteroid and cytokinin signaling was observed in generative cells and vegetative cells, respectively.
CONCLUSIONS
Our results suggest the asymmetric division of the microspore significantly reshapes the genome-wide distribution of H3K4me3. Selective loss of H3K4me3 in genes related to hormone signaling may contribute to functional differentiation of sperm cell lineage. This work provides new resource data for the epigenetic studies of gametogenesis in plants.
Topics: Solanum lycopersicum; Histones; Cell Lineage; Genome, Plant; DNA Methylation; Gene Expression Regulation, Plant; Pollen; Epigenesis, Genetic; Chromatin Immunoprecipitation Sequencing
PubMed: 38926660
DOI: 10.1186/s12870-024-05318-8 -
Brazilian Journal of Biology = Revista... 2024The identification of meliponicultural flora is fundamental for the preservation of bees, as well as enabling the development of pollinator management and reforestation...
Pollen analysis of honey and pollen stored by Melipona (Melikerria) fasciculata Smith, 1854 (Apidae Meliponini), in an Amazon and Cerrado transition area, Maranhão, Brazil.
The identification of meliponicultural flora is fundamental for the preservation of bees, as well as enabling the development of pollinator management and reforestation programs. In this context, this study aimed to investigate the types of pollen found in the honey and pollen pots of the Melipona fasciculata bee in Arari, State of Maranhão, between August 2022 and July 2023. 40 types of pollen were identified, distributed among 18 botanical families, with Fabaceae standing out (46.15% in pollen pots and 37.86% in honey pots), Myrtaceae (11.53% in pollen and 13.51% in honey) and Rubiaceae (7.69% in pollen and 5.40% in honey). Sapindaceae, in the honey pots, accounted for 5.40%. The other families showed lower percentages, 3.84% in the pollen pots and 2.70% in the honey pots. In terms of similarity, two distinct groups were observed in both the pollen and honey pots. In the pollen pots, group A (May-June ~ 97%) and group B (Feb-Mar ~ 99%) stood out, while in the honey pots, group A (Mar-Apr ~ 98%) and group B (Jun-Jul-Sept ~ 98%) showed the highest percentages. These findings highlight the wide range of resources used by the M. fasciculata species, as well asits preference for Fabaceae and Myrtaceae, due to the diversity and availability of trophic resources. An understanding of the meliponicultural flora is essential to support effective conservation strategies, which aim not only to guarantee the survival of the bees, but also to ensure the continued production of honey, a resource of great importance to local communities.
Topics: Pollen; Honey; Bees; Animals; Brazil; Seasons; Pollination
PubMed: 38922195
DOI: 10.1590/1519-6984.281066 -
Insects Jun 2024are predaceous mites that feed on phytophagous mites, pollens, and plant exudates and are known as one of the most potent biological pest management agents. is a...
are predaceous mites that feed on phytophagous mites, pollens, and plant exudates and are known as one of the most potent biological pest management agents. is a global mite that is difficult to manage because of its high population growth rates, necessitating alternative management measures like biological control. Regarding the functional response, the effects of temperature and prey density are some of the essential behaviors of natural enemies. This study investigates the effect of varying temperatures and prey densities on , a biological control agent for . The present results demonstrated the change in the functional response estimates when was reared at various temperatures and different prey densities. The results of the estimates regarding the searching efficiency () showed the highest value ( = 0.919) at 26 °C and the lowest value ( = 0.751) at 14 °C. The handling time per prey item () for the predatory mites changed with the temperature and prey density, showing the shortest handling time at 26 °C ( = 0.005) and the highest value at 14 °C ( = 0.015). The functional response curves matched the type II functional response model, demonstrating the inverse dependence of temperatures and prey density with a positive quadratic coefficient. The predation curves for showed a significant difference between the mean numbers of consumed at various prey densities and temperatures, illustrating a relationship between and Therefore, the results of this research may be utilized to forecast the behavior of and its usefulness in controlling populations.
PubMed: 38921159
DOI: 10.3390/insects15060444 -
Insects Jun 2024Hybrid rice results from crossing a male-sterile line (the A line) with a pollen doner (the restorer or R line). In 3-line hybrid breeding systems, a fertile B line is...
Hybrid rice results from crossing a male-sterile line (the A line) with a pollen doner (the restorer or R line). In 3-line hybrid breeding systems, a fertile B line is also required to maintain A line populations. Heterosis is defined as a condition of traits whereby the hybrid exceeds the average of the parental lines. Heterobeltiosis is where the hybrid exceeds both parents. Hybrid rice may display heterosis/heterobeltiosis for growth, yield and resistance to herbivores, among other traits. In a greenhouse experiment, we assessed the frequency of heterosis for resistance to the brown planthopper ( (BPH)), whitebacked planthopper ( (WBPH)) and yellow stemborer ( (YSB)) in eight hybrids under varying soil nitrogen conditions. We also assessed plant biomass losses due to herbivore feeding as an approximation of tolerance (the plant's capacity to compensate for damage). Nitrogen reduced resistance to all three herbivores but was also associated with tolerance to WBPH and YSB based on improved plant survival, growth and/or yields. Plant biomass losses per unit weight of WBPH also declined under high nitrogen conditions for a number of hybrids, and there were several cases of overcompensation in rice for attacks by this herbivore. There was one case of nitrogen-related tolerance to BPH (increased grain yield) for a hybrid line with relatively high resistance, likely due to quantitative traits. Heterosis and heterobeltiosis were not essential to produce relatively high herbivore resistance or tolerance across hybrids.
PubMed: 38921131
DOI: 10.3390/insects15060416 -
Advances in Respiratory Medicine May 2024Ragweed pollen allergy is the most common seasonal allergy in western Romania. Prolonged exposure to ragweed pollen may induce sensitization to pan-allergens such as...
Ragweed pollen allergy is the most common seasonal allergy in western Romania. Prolonged exposure to ragweed pollen may induce sensitization to pan-allergens such as calcium-binding proteins (polcalcins) and progression to more severe symptoms. We aimed to detect IgE sensitization to recombinant Amb a 9 and Amb a 10 in a Romanian population, to assess their potential clinical relevance and cross-reactivity, as well as to investigate the relation with clinical symptoms. rAmb a 9 and rAmb a 10 produced in were used to detect specific IgE in sera from 87 clinically characterized ragweed-allergic patients in ELISA, for basophil activation experiments and rabbit immunization. Rabbit rAmb a 9- and rAmb a 10-specific sera were used to detect possible cross-reactivity with rArt v 5 and reactivity towards ragweed and mugwort pollen extracts. The results showed an IgE reactivity of 25% to rAmb a 9 and 35% to rAmb a 10. rAmb a 10 induced basophil degranulation in three out of four patients tested. Moreover, polcalcin-negative patients reported significantly more skin symptoms, whereas polcalcin-positive patients tended to report more respiratory symptoms. Furthermore, both rabbit antisera showed low reactivity towards extracts and showed high reactivity to rArt v 5, suggesting strong cross-reactivity. Our study indicated that recombinant ragweed polcalcins might be considered for molecular diagnosis.
Topics: Humans; Immunoglobulin E; Cross Reactions; Rhinitis, Allergic, Seasonal; Romania; Calcium-Binding Proteins; Antigens, Plant; Allergens; Female; Male; Ambrosia; Rabbits; Adult; Plant Extracts
PubMed: 38921061
DOI: 10.3390/arm92030022 -
Antibodies (Basel, Switzerland) Jun 2024The proportion of patients with type I allergy in the world population has been increasing and with it the number of people suffering from allergic symptoms. Recently we...
The proportion of patients with type I allergy in the world population has been increasing and with it the number of people suffering from allergic symptoms. Recently we showed that prophylactic cell therapy employing allergen-expressing bone marrow (BM) cells or splenic B cells induced allergen-specific tolerance in naïve mice. Here we investigated if cell therapy can modulate an established secondary allergen-specific immune response in pre-immunized mice. We sensitized mice against the grass pollen allergen Phl p 5 and an unrelated control allergen, Bet v 1, from birch pollen before the transfer of Phl p 5-expressing BM cells. Mice were conditioned with several combinations of low-dose irradiation, costimulation blockade, rapamycin and T cell-depleting anti-thymocyte globulin (ATG). Levels of allergen-specific IgE and IgG1 in serum after cell transfer were measured via ELISA and alterations in cellular responses were measured via an in vitro proliferation assay and transplantation of Phl p 5 skin grafts. None of the tested treatment protocols impacted Phl p 5-specific antibody levels. Transient low-level chimerism of Phl p 5 leukocytes as well as a markedly prolonged skin graft survival were observed in mice conditioned with high numbers of Phl p 5 BMC or no sensitization events between the day of cell therapy and skin grafting. The data presented herein demonstrate that a pre-existing secondary allergen-specific immune response poses a substantial hurdle opposing tolerization through cell therapy and underscore the importance of prophylactic approaches for the prevention of IgE-mediated allergy.
PubMed: 38920972
DOI: 10.3390/antib13020048 -
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 -
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 -
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